Replacing the stage brakes on a 15-630 Specimen stage

Posted on November 21, 2023 by Randy

The 15-630 Specimen Stage is used on Perkin Elmer Physical Electronics 600 and 660 scanning Auger systems. The 15-630 is a precision sample stage that has micrometers for the X, Y, Z, tilt and rotation axis. The gear ratio is high in order to have precise small movements. To lock the positions into place, spring loaded .120” diameter high temperature plastic rods are employed. With use, these brakes wear down and the micrometers no longer hold the stage axis in place which in turn causes drift at higher magnifications.This blog post will show you how to replace the stage brakes.

The PHI (Physical Electronics) part number for the stage brakes is 605857 and as of this posting they go for $6.00 each.

To determine whether or not the stage brakes need to be replaced on a micrometer just move the micrometer a turn and see if it feels loose or slightly snug. If you can easily turn the knob back and forth then the brakes are worn out and need to be replaced. Usually only one or two micrometers need to have new stage brakes. But if you have never checked this before you may find that they are all loose and need to be replaced.

You will need to remove the knurled knob on the micrometer in order to replace the stage brakes. Before you attempt to remove the knurled knob, you will need a 183-6 Bristol wrench. You can get those from Bristol at this link –

https://bristolwrench.com/product-category/spline-long-arm/

But, since the original Bristol was sold a few years ago, the new Bristol sells the wrenches in packs of 10 minimum. So if you do not have a 183-6 Bristol wrench handy you can also use a 5/32″ Allen wrench.

Hold the knob firmly and press it towards the center of the stage as you turn the cap head screw that is inside the center of the knurled knob CCW until the screw is loose. Then, very slowly, pull the knurled knob off.

There are some springs inside two small holes that provide pressure on the two stage brakes. If you pull the knurled knob off quickly then the stage brake and possibly the spring will go flying.

Remove the worn stage breaks and insert the new ones into the holes.

Replace the knurled knob and insert the cap head screw. Hold the knurled knob firmly and press it in towards the center of the stage as you tighten the cap head screw.

Repeat this process for all of the micrometers that need new stage breaks.

Adjust indicator position

Each micrometer has an indicator that shows where the micrometer is in relation to the min and max movement for that micrometer. For example the Z is from +5mm to – 15mm.

To change the indicator, with the knurled knob off remove the shaft gear.

Next, spin the indicator gear until you have the indicator to the desired position. Then replace the center gear.

The Z axis indicator may need to be adjusted once in a while as it can slip. You can sent the actual Z position of the stage to as low as it will go and then set the indicator to -15mm. You will know that the Z indicator is off if you are having trouble loading your sample or getting the stage close enough for an elastic peak.

20-040 X-ray source power supply LOCAL REMOTE switch

Posted on May 30, 2023 by Randy

The 20-040 X-ray source power supply is used on some of the older PHI X-ray photoelectron spectroscopy (XPS) systems. There is a switch on the back of the 20-040 that needs to be set to the LOCAL position. When in the LOCAL position the high voltage is set by the user but the 32-095 or 32-096 X-ray source control turns the 20-040 high voltage on and off. Sometimes the LOCAL / REMOTE switch can become oxidized in which case the 20-040 high voltage may not turn on. This post explains how to remove the LOCAL / REMOTE switch and hard wire the board to the LOCAL position.

Make sure that the 20-040 main power switch is OFF and then unplug all cables from the back of the 20-040 and remove the 20-040 from the electronics console.

Remove the top cover (8 cross head screws).

Unscrew the nut on the LOCAL / REMOTE switch and also unscrew the two nuts on the 15 pin connector. Unplug the 3 pin connector on the top of the board, the larger bottom connector can stay attached.

On the back of the little board that the LOCAL / REMOTE switch is attached to you can see where the switch is soldered to the board. Un-solder and remove the switch. A solder sucker works well but you can also use some solder wick.

Solder some jumper wires between the pins as shown in the image below.

Reattach the 3 pin connector and then insert the 15 pin connector back into the slot and use the two nuts to attach the board to the back chassis. I also added a plastic screw and nut to block the hole that remains after removing the switch. You can also just leave that hole open.

Replace the cover and tighten the 8 cover screws.

Make sure that the 20-040 main power switch is still OFF and then insert the 20-040 back into the electronics console and reattach all the cables to the back of the 20-040.

Below is a table that shows the pin outs on the control cable that goes between the 32-095/6 and the 20-040.

Removing the LOCAL / REMOTE switch eliminates the switch as a cause of lack of high voltage with the 20-040. If your 20-040 does not work and can’t be repaired, then RBD Instruments provides a drop in replacement, the 20-042.

https://rbdinstruments.com/phi/x-ray-hv-supply.html

32-095 and 32-096 X-ray source control faulty capacitor – urgent!

Posted on May 4, 2023 by Randy

Recently, I have seen the same problem on several 32-095 and 32-096 X-ray source controls which are used on older Physical Electronics PHI X-ray photo electron spectroscopy systems.

The issue is that C9, a 680 uF electrolytic capacitor blows out and the electrolytic material leaks out on the board. Left unattended, the electrolytic etches and oxidizes the traces on the board.

If you have an older PHI XPS system that uses a 32-095 or 32-095 X-ray source control you should pull if out of the rack, remove the cover and inspect the board immediately.

If corrosion is present, then remove the board and remove C9. Note the polarity of C9 as the + indicator on the board may be etched away. Then, carefully clean the corrosion from the board as best as you can. If in the shop I use some Alconox and let it sit on the board for a while, then rinse with DI water and let the board dry overnight. In the field I have used isopropanol or methanol and cotton swabs. Note that if the traces are corroded badly then they may come off the board as you clean it. If so, you will need to use some fine copper wire to rebuild the traces.

Once the board is clean and dry, replace C9 with a new one. I will dig into this issue some more and try to determine why this problem occurs so often and come up with a permanent solution. In the meantime, I would recommend that the C9 capacitor be replaced every 5 years.

The pictures below show where C9 is located on the control board and what the corrosion looks like.