Power Supply Troubleshooting Chart - North Star DIMENSION Service Manual

TROUBLESHOOTING
(cont.) Testing the Central Module Power Supply
Power Supply Troubleshooting Chart
Symptom Explanation Solution
+5VDC is low. R146 is out
of adjustment.
Set R146 for a bus board reading of +5.10VDC when
making the adjustment.
No +5VDC.
IC1 failed;
Either D30 or
D31 is
shorted.
Replace the power supply.
+12VDC is
low.
R194 is out
of adjustment.
Adjust R194 to specification.
No +12VDC . Either D63,
T14 or T15 is
opened.
Replace the power supply.
No +5VDC,
+12VDC or
-12VDC.
IC1 failed ;
either D30 or
D31 is
shorted.
Replace the power supply.
No -12VDC. IC2 failed.
Replace IC2 with a + 12VDC regulator.
DIMENSION Service Manual 2-59