ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Table 4-20. Computer Power Supply Testing and Troubleshooting Continued
Malfunction
indication/corrective action
Test procedure
Normal indication
2x. Set COMP PS switch to OFF
COMP PS ON indicator goes
off
2y. Set REFERENCE AMB TEMP V LAMP
switch to O V
22. Set FUNCTION switch to COMP PS +15V
PREC
2aa. Set COMP PS switch to ON
COMP PS ON indicator lights
2ab. Connect DVM test leads to COMP PWR
DVM indicates +14.8 to
If the voltage is out of tolerance,
+15.2V
replace 5V power supply circuit card
SPLY PREC + 15V and PWR RTN test
jacks
assembly A1
2ac. Set COMP PS switch to OFF
COMP PS ON indicator goes
off
2ad. Set FUNCTION switch to COMP PS
-15V PREC
2ae. Set COMP PS switch to ON
COMP PS ON indicator lights
DVM indicates -14.7 to
If the voltage is out of tolerance,
2af. Connect DVM test leads to COMP PWR
-15.3V
replace 5V power supply circuit card
SPLY PREC -1 5V and PWR RTN test
assembly A1
jacks
2ag. Set COMP PS switch to OFF
COMP PS ON indicator goes
off
2ah. Set FUNCTION switch to COMP PS +5V
2ai. Set COMP PS switch to ON
COMP PS ON indicator lights
DVM indicates +4.8 to +5.2V
2aj. Connect DVM t est leads to COMP PWR
If the voltage is out of tolerance,
replace 5V power supply circuit card
SPLY +5V and PWR RTN test jacks
assembly A1
2ak. Disconnect DVM from PSTS
2al. Set COMP PS switch to OFF
COMP PS ON indicator goes
off
2am. Set MODE switch to NO LOAD
2an. Connect oscilloscope to POR* and
PWR RTN test jacks
2ao. Adjust oscilloscope vertical sensitivity
to 2 volts/division and center trace, then
set to DC coupling
4-129
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