{"id":3643,"date":"2022-11-15T07:30:00","date_gmt":"2022-11-15T15:30:00","guid":{"rendered":"https:\/\/www.rbdinstruments.com\/blog\/?p=3643"},"modified":"2023-12-13T14:40:31","modified_gmt":"2023-12-13T22:40:31","slug":"transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components","status":"publish","type":"post","link":"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/","title":{"rendered":"Transistor Heat Sink Fatigue"},"content":{"rendered":"\n<p>Some of the older PHI electronic units have a type of heat sink with a built-in spring tab (shown in the picture below) that forces the back of a transistor into the heat sink.&nbsp; Over time, the spring tab can lose tension (most likely due to heat induced metal fatigue) and then the transistor no longer connects to the heat sink, eventually resulting in the transistor failing due to overheating.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?ssl=1\"><img data-attachment-id=\"3644\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/spring-tab\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Spring-tab\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg\" alt=\"\" class=\"lazy wp-image-3644\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3644\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/spring-tab\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Spring-tab\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3644\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Spring-tab.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>For units such as the 32-100 Electron Multiplier Supply, overheated transistors are often the cause of multiplier voltage output problems.&nbsp;<\/p>\n\n\n\n<p>For this blog post we will look at a 32-100 electron multiplier supply with no output on the CMA high voltage output.&nbsp;The problem was isolated to a bad TIP120 transistor which shorted out and melted because the back of the transistor separated from the heat sink over time.   <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?ssl=1\"><img data-attachment-id=\"3645\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/tip-120-transistor-in-hv-circuit\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=1094%2C714&amp;ssl=1\" data-orig-size=\"1094,714\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"TIP-120-transistor-in-HV-circuit\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=300%2C196&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=584%2C381&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"381\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C381&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit-1024x668.jpg\" alt=\"\" class=\"lazy wp-image-3645\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=1024%2C668&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=300%2C196&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=768%2C501&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=460%2C300&amp;ssl=1 460w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?w=1094&amp;ssl=1 1094w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3645\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/tip-120-transistor-in-hv-circuit\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=1094%2C714&amp;ssl=1\" data-orig-size=\"1094,714\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"TIP-120-transistor-in-HV-circuit\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=300%2C196&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?fit=584%2C381&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"381\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=584%2C381&#038;ssl=1\" alt=\"\" class=\"wp-image-3645\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=1024%2C668&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=300%2C196&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=768%2C501&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?resize=460%2C300&amp;ssl=1 460w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/TIP-120-transistor-in-HV-circuit.jpg?w=1094&amp;ssl=1 1094w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>In addition to replacing the TIP120 transistor, we also modified the heat sink to ensure a good contact with the transistor.&nbsp;<\/p>\n\n\n\n<p>To modify the heat sink, you need to first remove the defective transistor and then remove the heat sink.&nbsp; You will need a hot soldering iron as the heat sink has enough mass that it will drain away some of the heat from the soldering iron.&nbsp;&nbsp; You can use a solder sucker or some solder braid to remove the solder from the heat sink contacts.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?ssl=1\"><img data-attachment-id=\"3646\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/remove-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Remove-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg\" alt=\"\" class=\"lazy wp-image-3646\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3646\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/remove-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Remove-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3646\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Remove-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>Once the heat sink as been removed, break off the spring tab.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?ssl=1\"><img data-attachment-id=\"3648\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/20221102_164629_resized\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=1512%2C1512&amp;ssl=1\" data-orig-size=\"1512,1512\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"20221102_164629_resized\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized-1024x1024.jpg\" alt=\"\" class=\"lazy wp-image-3648\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=1024%2C1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=768%2C768&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?w=1512&amp;ssl=1 1512w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?w=1168&amp;ssl=1 1168w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3648\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/20221102_164629_resized\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=1512%2C1512&amp;ssl=1\" data-orig-size=\"1512,1512\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"20221102_164629_resized\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3648\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=1024%2C1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?resize=768%2C768&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?w=1512&amp;ssl=1 1512w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164629_resized.jpg?w=1168&amp;ssl=1 1168w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?ssl=1\"><img data-attachment-id=\"3649\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/20221102_164636_resized\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=1512%2C1512&amp;ssl=1\" data-orig-size=\"1512,1512\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"20221102_164636_resized\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized-1024x1024.jpg\" alt=\"\" class=\"lazy wp-image-3649\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=1024%2C1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=768%2C768&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?w=1512&amp;ssl=1 1512w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?w=1168&amp;ssl=1 1168w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3649\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/20221102_164636_resized\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=1512%2C1512&amp;ssl=1\" data-orig-size=\"1512,1512\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"20221102_164636_resized\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3649\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=1024%2C1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?resize=768%2C768&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?w=1512&amp;ssl=1 1512w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/20221102_164636_resized.jpg?w=1168&amp;ssl=1 1168w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>Next, drill a small hole in the back of the heat sink where the indent is located. We used a 9\/64&#8243; drill bit since we needed to clear a 6-32 screw and lock nut.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?ssl=1\"><img data-attachment-id=\"3647\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/drill-hole-here\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Drill-hole-here\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg\" alt=\"\" class=\"lazy wp-image-3647\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3647\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/drill-hole-here\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Drill-hole-here\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3647\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/Drill-hole-here.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p> Put some heat sink compound or conductive tape on the back of the replacement transistor.&nbsp; This is necessary to ensure good thermal transfer from the transistor to the heat sink.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?ssl=1\"><img data-attachment-id=\"3651\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/heat-sink-compound\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"heat-sink-compound\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg\" alt=\"\" class=\"lazy wp-image-3651\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3651\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/heat-sink-compound\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"heat-sink-compound\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3651\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/heat-sink-compound.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>Use a screw and lock nut to attach the transistor to the heat sink.&nbsp; Make sure that the transistor is centered in the heat sink.&nbsp;&nbsp; In this case we also added another small heat sink to the back of the original heat sink to add some additional cooling for the transistor.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?ssl=1\"><img data-attachment-id=\"3652\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/centered-tip120\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"centered-TIP120\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg\" alt=\"\" class=\"lazy wp-image-3652\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3652\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/centered-tip120\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"centered-TIP120\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3652\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/centered-TIP120.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?ssl=1\"><img data-attachment-id=\"3653\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/extra-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"extra-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg\" alt=\"\" class=\"lazy wp-image-3653\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3653\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/extra-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"extra-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3653\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/extra-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>Next, insert the transistor leads into the holes on the board and insert the heat sink into the larger holes in the board.&nbsp;&nbsp; Solder the heat sink and the transistor leads. &nbsp;Cut the excess leads from the transistor and remove any excess flux from the board.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?ssl=1\"><img data-attachment-id=\"3654\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/new-transistor-with-modified-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"new-transistor-with-modified-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg\" alt=\"\" class=\"lazy wp-image-3654\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3654\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/new-transistor-with-modified-heat-sink\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"new-transistor-with-modified-heat-sink\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3654\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p>Now that we have replaced the transistor and improved the transistor to heat sink contact, the 32-100 should perform well for many years.<\/p>\n\n\n\n<p>Since we were replacing the one defective TIP120 transistor, we also replaced the one for the SED supply as well (and modified its heat sink) as a preventive measure. &nbsp;In this case we could not add the extra small heat sink due to a tight clearance to the nearby transformer. Even so, the improved contact to the heat sink will provide improved heat transfer from the transistor and result in improved reliability.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?ssl=1\"><img data-attachment-id=\"3655\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/sed-tip120\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"SED-TIP120\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=584%2C584&#038;ssl=1\" data-original=\"https:\/\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg\" alt=\"\" class=\"lazy wp-image-3655\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><noscript><img data-attachment-id=\"3655\" data-permalink=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/sed-tip120\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=756%2C756&amp;ssl=1\" data-orig-size=\"756,756\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"SED-TIP120\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=300%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?fit=584%2C584&amp;ssl=1\" decoding=\"async\" loading=\"lazy\" width=\"584\" height=\"584\" src=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?resize=584%2C584&#038;ssl=1\" alt=\"\" class=\"wp-image-3655\" srcset=\"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?w=756&amp;ssl=1 756w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/SED-TIP120.jpg?resize=150%2C150&amp;ssl=1 150w\" sizes=\"(max-width: 584px) 100vw, 584px\" data-recalc-dims=\"1\" \/><\/noscript><\/a><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>Need help with your older PHI (Physical Electronics) surface analysis system electronics (or optics)?  <a href=\"https:\/\/rbdinstruments.com\/contact.html\" data-type=\"link\" data-id=\"https:\/\/rbdinstruments.com\/contact.html\" target=\"_blank\" rel=\"noreferrer noopener\">Contact us for more information<\/a>.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Method to improve contact to transistor heat sink in older PHI electronic units <a href=\"https:\/\/www.rbdinstruments.com\/blog\/transistor-heat-sink-fatigue-on-older-phi-surface-analysis-electronic-components\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":3654,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[166],"tags":[402,400,401],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2022\/11\/new-transistor-with-modified-heat-sink.jpg?fit=756%2C756&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p2DEXo-WL","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":1591,"url":"https:\/\/www.rbdinstruments.com\/blog\/parts-that-fail-in-older-phi-electronic-units\/","url_meta":{"origin":3643,"position":0},"title":"Parts that fail in older PHI electronic units","author":"Randy","date":"October 31, 2015","format":false,"excerpt":"Common parts that fail in various older PHI electronic units This post lists common parts that fail in various PHI electronic units such as electron gun controls, analyzer controls and electron multiplier supplies. The part designations show an example of where a partial part may be used in a control.\u2026","rel":"","context":"In &quot;Operation and Calibration Procedures&quot;","block_context":{"text":"Operation and Calibration Procedures","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/operation-and-calibration-procedures\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1328,"url":"https:\/\/www.rbdinstruments.com\/blog\/troubleshooting-electronics-resources\/","url_meta":{"origin":3643,"position":1},"title":"Troubleshooting electronics resources","author":"Randy","date":"January 30, 2020","format":false,"excerpt":"1-30-20\u00a0 \u00a0I updated this blog post to include a video on how to isolate a thermally unstable electronic component using a heat gun and cool spray. When a problem develops with your XPS or AES spectrometer and you contact RBD Instruments for assistance, we frequently hear the same question \u2013\u2026","rel":"","context":"In &quot;Miscellaneous&quot;","block_context":{"text":"Miscellaneous","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/miscellaneous\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/plugins\/jquery-image-lazy-loading\/images\/grey.gif?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":3199,"url":"https:\/\/www.rbdinstruments.com\/blog\/72-100-electron-multiplier-supply-notes\/","url_meta":{"origin":3643,"position":2},"title":"72-100 Electron Multiplier Supply Notes","author":"Randy","date":"April 2, 2021","format":false,"excerpt":"Notes on to test and repair the 72-100 electron multiplier supply used on older PHI Auger systems.","rel":"","context":"In &quot;General Optics and Vacuum&quot;","block_context":{"text":"General Optics and Vacuum","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/general-optics-and-vacuum\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2021\/04\/Extended-72-100-board.jpg?fit=1200%2C1200&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2021\/04\/Extended-72-100-board.jpg?fit=1200%2C1200&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2021\/04\/Extended-72-100-board.jpg?fit=1200%2C1200&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2021\/04\/Extended-72-100-board.jpg?fit=1200%2C1200&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":4064,"url":"https:\/\/www.rbdinstruments.com\/blog\/a-numbers-for-phi-units\/","url_meta":{"origin":3643,"position":3},"title":"&#8220;A&#8221; Numbers for PHI units","author":"Randy","date":"September 9, 2024","format":false,"excerpt":"A numbers for older PHI surface analysis systems control units.","rel":"","context":"In &quot;General Optics and Vacuum&quot;","block_context":{"text":"General Optics and Vacuum","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/general-optics-and-vacuum\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2024\/09\/32-150-A116.jpg?fit=1200%2C540&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2024\/09\/32-150-A116.jpg?fit=1200%2C540&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2024\/09\/32-150-A116.jpg?fit=1200%2C540&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2024\/09\/32-150-A116.jpg?fit=1200%2C540&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":1228,"url":"https:\/\/www.rbdinstruments.com\/blog\/test-procedure-phi-vf-preamplifiers\/","url_meta":{"origin":3643,"position":4},"title":"Test procedure for PHI V\/F preamplifiers","author":"Randy","date":"October 20, 2014","format":false,"excerpt":"Overview: Most of the older PHI AES systems use a voltage to frequency converter (V\/F) to convert the electron multiplier auger signal output from a small current into a frequency so that the computer can count the signal. At the time these systems were designed, this was a more cost\u2026","rel":"","context":"In &quot;General Optics and Vacuum&quot;","block_context":{"text":"General Optics and Vacuum","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/general-optics-and-vacuum\/"},"img":{"alt_text":"preamp-96A-col-and-L2","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2014\/10\/preamp-96A-col-and-L2.png?fit=417%2C371&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":860,"url":"https:\/\/www.rbdinstruments.com\/blog\/how-to-test-a-97-sed-preamplifier\/","url_meta":{"origin":3643,"position":5},"title":"How to test a 97 SED preamplifier","author":"Randy","date":"November 8, 2013","format":false,"excerpt":"Older PHI scanning auger systems use the model 97 SED preamplifier to obtain secondary electron images. Occasionally you will not be able to get a TV image on your scanning auger system but are not sure what the problem is. 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