363-205-401
Power Up: DLP-518
Issue 7, March 1997
Page 3 of 4
15. Check wiring on power shelf between 336A RECTIFIER and PRU using
SD-7C119-01. Repeat procedure from Step 13 after locating and correcting
trouble.
16. On PRU, connect DMM test leads to
−
20HZ jack and FR GND jack.
Response:
DMM indicates between
−
50 and
−
60 volts.
17. Leave DMM test leads connected to
−
20HZ and FR GND jacks and condition
DMM to measure AC volts.
Response:
DMM indicates between 90 and 110 volts.
18. Is AC/DC ringing voltages present at
−
20HZ jack on the PRU?
If YES, then proceed to Step 20.
If NO, then continue with Step 19.
19. Check wiring on power shelf between 3C( ) RINGING GENERATOR and PRU
using SD-7C119-01. Repeat procedure from Step 16 after locating and cor-
recting trouble.
20. Condition DMM to measure DC volts.
21. On PRU, connect DMM test leads to +20HZ jack and FR GND jack.
Response:
DMM indicates between 50 and 60 volts.
22. Leave DMM test leads connected to +20HZ and FR GND jacks and condition
DMM to measure AC volts.
Response:
DMM indicates between 90 and 110 volts.
23. Is AC/DC ringing voltages present at +20HZ jack on the PRU?
If YES, then proceed to Step 25.
If NO, then continue with Step 24.
24. Replace PRU and repeat procedure from Step 2.
25. Is another PRU to be installed at this time?
If YES, then proceed to Step 1.
If NO, then STOP. YOU HAVE COMPLETED THIS PROCEDURE.