IBM 6648 - Manual (Page 121)

Keyboard
Note
If a mouse or other pointing device is attached, remove it to see if the
error symptom goes away. If the symptom goes away, the mouse or
pointing device is defective.
001
- Power-off the computer.
Disconnect the keyboard cable from the system unit.
Power-on the computer and check the keyboard cable connector on the
system unit for the voltages shown.
All voltages are 5%.
Pin
1
2
3
4
5
6
Voltage (Vdc)
+ 5 . 0
Reserved
Ground
+ 5 . 0
+ 5 . 0
Reserved
1
6
2
3 4
5
ARE THE VOLTAGES CORRECT?
If YES, proceed to 003 .
If NO, continue with
002 .
002
Replace the system board.
003
On keyboards with a detachable cable, replace the cable. If the problem
remains or if the cable is permanently attached to the keyboard, replace the
keyboard. If the problem remains, replace the system board.
Printer
1. Make sure the printer is properly connected and powered on.
2. Run the printer self-test.
Chapter 3. Types 6058/6059/6269/6578/6579 107