IBM PCjr

Error
Description
Power
Supply
Check
Diagnostic Action
5. Measure the +24 Vdc (use ground pin on
the driver circuit card).
Pin No.
Min.
Voltage
Max.
Voltage
CN3-I8
21.6 Vdc 26.4 Vdc
6.
Is +24 Vdc within range?
YES: Power supply checks good.
NO: Go to step 6.
Measure DC voltages (on 60-volt scale) on
pins CN6-1 and CN6-2 located on control
circuit card (use the DC ground pin on the
driver circuit card for common lead). Find
the difference in the two readings.
Is the difference 0.5 to 0.9 Vdc?
YES:
NO:
Replace both control cards. See
Section 4, "Removal/Replacement
and Adjustments."
Replace the heat sink/power
transistor assembly. See Section 4,
"Removal/Replacement and
Adjustments."
Graphics Printer 3-1400-9