When the 32-095 X-ray source control is not working properly there are some easy possible solutions that you can check before sending the unit to RBD Instruments Inc. for repair.
If the problem is that one filament works but the other one does not, then you should check the fuses located on the filament power supply board inside the 32-095 X-ray source control in the back left hand corner of the unit. (The other possibility is that the x-ray source filament is open.) With the 32-095 power off, slide the unit out and remove the cover, then measure the resistance on the fuses. Usually it is easiest to just completely unplug the 32-095 and remove it from the electronics rack.
The fuses are 5 amp slow blow and are shown in the board layout figure below.
Filament power supply board fuses
The next most common problem is instability in the controller or flashing digits on the digital panel meter. These can be caused by high AC ripple on the +/-15V or +5 V supplies on the local power supply board which is located in the front left hand side of the 32-095.
The figure below shows the layout of the local power supply board and the location of the +/-15V and +5V supplies.
The picture below shows the points where you measure the +5v supply. To measure the +5V supply, connect your test clips to the pins as shown in the picture below. Turn on the 32-095 power and then measure both the DC and AC voltage using a DVM. The correct value is +5.0 V DC (+/- 100 mV) and the AC ripple should be less than 10mV. If the +5V supply has a problem the DC will be more like 4V and the AC will be 1 to 2V. Power supply board problems are usually caused by bad capacitors.
The pictures below show the test points for the + and – 15V supplies. The correct voltage values are + and – 15.0V (+/- 200 mV) and the AC ripple should be less than 20mV. If the DC voltage is low and the AC ripple is high then the supply has a problem.
32-095 local power supply board +15V
The figures below show the +5 and +/- 15V local power supply board schematics.
15 V schematic
Below is a table that lists common problems and possible solutions. Sometimes the problems are easy to fix, but often the problem may be a hard to find bad capacitor, diode or integrated circuit.
|No current on one filament||Bad power supply board fuse, open filament on source|
|No filament current but fuse is OK||Bad PIC 645 regulator|
|Unstable operation||Bad capacitor on local power supply board|
If the problem is not an easy fix then RBD Instruments can repair your 32-095/96 x-ray source control and also provide you with a loaner unit to use while we are repairing yours.
Additional test info:
04-500/548 X-Ray Source Filament Test
The following information is helpful in testing the condition of the filaments in 04-500 or 04-548 15 kV dual anode X-ray sources and in troubleshooting the 32-095 X-ray source control.
On the big filament connector on the source, pins A and B (filament 1) and C and D (filament 2) should have less than 1 ohm of resistance. All pins should be open to ground.
The HV connector (anode) should be open to ground. Check that with the X-ray high voltage supply OFF and the HV cable to the source disconnected.
Follow the 32-095 Outgas/Activate procedure in the 32-095 manual.
To bench check the 32-095, short pins A and B on the Pressure Interlock connector, and pins A and E on the Pump Control connector.
You can use two large paper clips as dummy loads when testing the filament current. Put the clips on the end of the cable or on the filament connector on the back of the 32-095.