IBM 5251 Series Maintenance Information Manual page 43

117
(continued)
- Power off.
- Disconnect the MSR cable.
Power on.
Probe the' -station 1/2 jumper' signal on the
interposer at connector D of the MSR card.
Is the line at an Up level?
Y N
- Check for proper positioning of the jumpers (118).
- Inspect the interposer.
- Replace the MSR card (119).
- Reconnect the MSR cable.
Power off.
- Reconnect the MSR cable.
- Power on.
Probe the five register signals at connector D of the
MSR card.'
Are both probe lights off for any line?
Y N
117
- Replace the MSR card (119).
Inspect the interposer.
Replace the planar; set the jumpers correctly on the
new planar (103) (105).
Suggested action for an intermittent problem:
• Analyze the suspected line; inspect all the connector
contacts.
• Replacement sequence:
- MSR card
- MSR assembly
- Planar
Maintenance Procedures 5251 MIM 1-25