IBM 5251 Series Maintenance Information Manual page 39

116
(continued)
- Probe the' -raw data' signal on the interposer test
pins at connector D of the MSR card.
- Pass the test card through the reader.
Does the line pulse?
Y N
- Power off.
- Disconnect the MSR cable.
- Power on.
- Probe the' -raw data' signal on the interposer at
connector D on the MSR card.
Is the line at an Up level?
Y N
Replace the MSR card (119).
Reconnect the MSR cable.
Replace the MSR assembly (119).
- Power off.
- . Disconnect the MSR cable.
Power on.
- Probe the' -raw data' Signal on the interposer at
connector D of the MSR card.
Is the line at an Up level?
Y N
Replace the MSR card (119).
- Reconnect the MSR cable.
- Power off.
- Reconnect the MSR cable.
- Power on.
- Probe the register 5 bit lines at connector C of the
MSR card.
Are both probe lights off for any line?
Y N
- Replace the MSR card (119).
- Inspect the interposer.
- Replace the planar; set the jumpers correctly on the
new planar (103) (105).
116
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 1-21