IBM 5251 Series Maintenance Information Manual page 83

140
(continued)
- Probe' -cable check B' (012) at the planar.
Is the line at a Down level?
Y N
140
- Check for an open through the cable and keyboard
logic PC board back to ground on the planar.
Inspect the interposer.
Replace the planar; set the jumpers correctly on the
new planar (103) (105).
Suggested action for an intermittent problem:
• Jumper B02 to 012
• If the problem still occurs, replace the planar. If the
problem does not occur, the cable or keyboard logic
PC board could be open.
Maintenance Procedures 5251
MIM
1-65