IBM RS/6000 SP manual Step, SP Switch function MAP

SP Switch function (MAP 0620)

Step 0620-033

All ground straps connecting the frames make adequate contact at both ends.

1.Disconnect clock source data cable at S00-BH-J3, J5, J7, or J9, then reconnect to SP Switch. (This is done to eliminate clocking noise from cable.)

2.Find a processor node in the ªproblemº frame which is usable for service. This will be used as the ªtestº processor node.

3.Run advanced diagnostics on ªcss0º on the ªtestº processor node and its associated switch port. v Do not perform cable wrap test.

vRefer to ″Running diagnostics in a processor node″ in RS/6000 SP: System Service Guide.

4.Look for an SRN indicating a clock problem, such as ªExternal clockº being listed as one of the failing components.

Note: Do not exit from diagnostics at this time, as it may be used in the following steps.

5.Do the ªcss0º diagnostics fail with an indication of a clock problem?

vIf yes, go to ªStep 0620-036º on page 1-34.

vIf the diagnostics did not fail with an indication of a clock problem:

a.If this the first time at this step, go to ªStep 0620-034º.

b.If this the second time through this step, go to ªStep 0620-043º on page 1-36 to verify fix.

Step 0620-034

The first time you went through ªStep 0620-033º, the diagnosticsdid not fail with an indication of a clock problem.

1.Disconnect the switch data cable corresponding to the selected clock at the SP Switch.

2.Run advanced diagnostics on ªcss0º on the ªtestº processor node and its associated switch port. v Do not perform cable wrap test.

vRefer to ″Running diagnostics in a processor node″ in RS/6000 SP: System Service Guide.

3.Look for an SRN indicating a clock problem, such as ªExternal clockº being listed as one of the failing components.

Note: Do not exit from diagnostics at this time, as it may be used in the following steps.

4.Do the ªcss0º diagnostics fail with an indication of a clock problem?

vIf yes:

a.Problem is not in the SP Switch.

b.Replace the switch data cable corresponding to the selected clock, reconnecting it at both SP Switches.

c.Go to ªStep 0620-040º on page 1-35.

vIf no, go to ªStep 0620-035º.

Step 0620-035

The ªcss0º diagnosticsdid not fail with an indication of a clock problem. This indicates that the problem is related to the clock selection in this SP Switch.

1.Replace the clock card in this SP Switch.

v Make sure to connect all cables connected to the clock card.

2.Reinstall only the two switch data cables which are not selected and the switch data cable to the ªtestº processor node.

v Do not connect the remaining switch data cables at this time.

3.Reconnect cables S00-BH-P1 and S00-BH-P2 at the rear of the SP Switch.

4.Put the SP Switch's circuit breaker into the On (`1') position.

Chapter 1. Maintenance Analysis Procedures (MAPs) 1-33