TM 11-6625-3081-23
7-21. PHOTOMULTIPLIER BRACKET ASSEMBLY 2A1A1A7 AND PHOTOMULTIPLIER TUBE
(PMT/LED SOURCE)
7-21
INPUT CODE:
PMTLED (cont)
d. SEGMENT 2
1. VDT DISPLAY
PMT HIGH VOLTAGE TEST POINT READING IN ERROR.
PERFORM THE FOLLOWING REPLACE
ACTIONS IN THE ORDER LISTED.
(REFERENCE TM 11-6625-3081-23 FOR REPLACEMENT
PROCEDURES.)
REF. DES.
PART NO.
NAME
1. 2A2A13XX
AC4720
DIFF. INPUT CCA (J7)
2. 2A2A6XX
HP69331B
DIGITAL OUTPUT CCA (SLOT 409)
3. 2A2A7A4
13081572
RELAY ASSY.
4. 2A2A13
13081746
A/D CONVERTER
5. 2A1A1A6
13081943-19
POWER SUPPLY ASSY.
6. 2A1A1A2A11
13081425-19
SWITCH ASSY.
2. CORRECTIVE ACTION - SEGMENT 2
(a) Remove Differential Input CCA 2A2A13XX (slot J7). Check contacts of
mating connectors and repair if required.
Install replacement 2A2A13XX
and perform PMTLED test.
If PMTLED test passes, no further action
required.
If this segment displayed again, proceed to (b). If another
segment displayed, proceed to that segment and continue
troubleshooting.
(b) Remove Digital Output CCA 2A2A6XX (slot 409). Check contacts of mating
connectors and repair if required.
Install replacement 2A2A6XX and
perform PMTLED test.
If PMTLED test passes, no further action
required.
If this segment displayed again, proceed to (c). If another
segment displayed, proceed to that segment and continue
troubleshooting.
(c) Remove Relay Assembly 2A2A7A4.
Check contacts of mating connectors and
repair if required.
Install replacement 2A2A7A4 and perform PMTLED
test.
If PMTLED test passes, no further action required.
If this
segment displayed again, proceed to (d).
If another segment displayed,
proceed to that segment and continue troubleshooting.
(d) Remove A/D Converter 2A2A13.
Check contacts of mating connectors and
repair if required.
Install replacement 2A2A13 and perform PMTLED
test.
If PMTLED test passes, no further action required.
If this
segment displayed again, proceed to (e).
If another segment displayed,
proceed to that segment and continue troubleshooting.
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