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Troubleshooting
Before attempting to troubleshoot the 002 Option Board, ensure that the fault is with the option itself and not with the main
power supply. This can be accomplished by removing the top cover, inside cover and disconnecting the two ribbon cables
from the A2 Control board and checking the operation of the main supply. Otherwise troubleshoot the option board as
described in the following paragraphs.
Removal of the Option Board. To facilitate troubleshooting the 002 Option the board can be removed from the power
supply and electrically connected via the ribbon cables from Service Kit's 06033-60005 or 5060-2665. To remove the
circuit board proceed as follows:
a. Turn off power supply and disconnect line cord.
b. Disconnect option I/O cable from J3 on rear panel and remove the two screws that secure option board to rear panel.
c. Disconnect the ribbon cables from the A2 Control board.
d. Remove option board by lifting the board by the front edge and sliding the board toward the front of the power supply.
e. Reconnect the option board to the A2 Control board using the extended ribbon cables from the Service Kit, and pace
the option board on an insulated surface next to the power supply.
f. Be careful that the option board lies securely on insulating material and does not touch any part of the main power
supply.
Isolating Faulty Circuit. It is apparent which function is not operating properly, proceed to the appropriate paragraph. If
the problem involves more than one function check the bias voltages from connectors J1 and J2 and the ± 11.8V on the
option board.
Troubleshooting Resistance and Voltage Programming
a. Confirm that the problem is on the option board by disconnecting the ribbon cables from the A2 Control Board and
attempting to program the supply via the rear panel terminal strip.
b. Check ± 15V and ± 11.8V supplies.
c. Check for a problem in the programming protection circuit. This circuit should draw about 2µA from the programming
lines.
d. Check that W3 and W4 are installed and S1 is in proper position .
Troubleshooting Current Programming
a. Check ± 15V and ± 11.8V supplies.
b. Proceed to test set-up shown in Figure A-11 and/or A-12.
c. Put S1 in V, R position and see if varying the 0-20V voltage source produces a 0-5 volt DC level across R44 or R39. If
not, check op-amps and associated circuitry.
d. Put S1 in I position and see if varying voltage source from 0 to 20 volts produces a 0-5Vdc level at W3 or W4. If not
check relay and programming protection circuit.