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
2.
C O M P U T E R POWER
SUPPLY TEST.
2a. Set switches as follows:
Switch
Setting
COMP PS
OFF
INPUT
POWER
PSTS
OFF
INPUT
POWER
UUT
OFF
MODE
OVERLOAD
FUNCTION
COMP PS
+ 5V
REFERENCE
A M B TEMP
V LAMP
0 VDC
OFF
SELF TEST
2b. Turn on external +28V power
source
2c. T u r n on external 0 to +40V
power source and adjust to 0V.
Set current limit to 10 amps
2d. Set INPUT POWER PSTS cir-
PSTS fan comes on
cuit breaker to ON
2e. Press POWER SUPPLY TEST
POWER SUPPLY TEST SET ON
SET ON switch-indicator. Set
switch-indicator goes on
MODE switch to NO LOAD.
2f. Set INPUT POWER UUT cir-
cuit breaker to ON
2g. Set COMPT PS switch to ON.
If a short is indicated, exchange 5V
Current drawn from 0 to +40V ex-
power s u p p l y c i r c u i t c a r d
Gradually increase external 0
ternal power source is less than 7
to +40V power source to +24
a s s e m b l y A1, then 15V power
amps and COMP PS ON indicator
supply circuit card assembly A2,
lights
( 0 . 5 ) V . Measure voltage at
then wiring harness A3
C O M P U T E R POWER SUP-
PLY PWR IN and PWR RTN
test jacks
2h. Set COMP PS switch to OFF,
If indicator light does not go off
COMPS PS ON indicator goes off,
when COMP PS switch is set to
then to ON
then lights
OFF, replace 15V power supply
circuit card assembly A2
If indicator does not stay on when
COMP PS switch is set to ON, try
replacing 5V power supply circuit
card assembly A1, or 15V power
supply circuit card. assembly A2,
or wiring harness A3
Change 2
4-127
Previous Page
