IBM 5150 Hardware Maintenance Manual page 167

Error
Description Diagnostic Action
Control
1.
Position Printer Power switch to ON.
Panel Measure voltages at CN3 (see Section 5, ~
"Locations") as shown in chart below. Use
ground on Driver Circuit card.
Min
Max
Pin no. voltage voltage
CN3-16 +4.5 Vdc +5.5 Vdc
CN3-20 +12.6 Vdc +15.4 Vdc
CN3-l8 +21.6 Vdc +26.4 Vdc
Are all voltages correct?
YES:
Go to step 2.
r-....
NO:
Go to page 1400-6, "Power Supply
Check."
2. Power off the Printer. Disconnect the
parallel printer cable at the printer.
Insert forms. Power on.
Are the Power, Ready, and Online lights on?
YES:
Go to step 6.
NO:
Is the alarm sounding and the No
Paper light on?
YES:
Go to page 1400-24, "False
End-of-Forms Alarm."
NO:
Go to step 3.
1400-26