Step 1520-4; Step 1520-5; Step 1520-6 - IBM RS/6000 44P 270 Service Manual

Step 1520-4

The power supply is working normally.
1. Unplug the power cord from the system unit.
2. Press and hold the power-on switch on the operator panel for a few seconds to
discharge the power supply.
3. Plug the power connectors (P1, P2, P3, P4, P5 and P6) into the power supply.
4. Plug the power cord into the system unit.
If a cooling fan does not turn, the system will try to power up and then turn off when the
power-on switch on the operator panel is pressed (but not when the switch on the
power supply is pressed and held).
While holding the power supply switch do all the cooling fans turn?
NO
YES

Step 1520-5

Press the power-on switch on the operator panel to turn on the power.
Does the power LED on the operator panel come on and stay on?
NO
YES

Step 1520-6

1. Unplug the power cord from the system unit.
2. Record the location of all the adapters. Label and record the location of any cables
attached to the adapters. Remove all the adapters.
3. Remove all the memory cards.
4. If two processor cards are installed, remove the lower one.
5. Unplug the power cable from the SCSI backplane.
6. Unplug the power cables from all the SCSI devices.
7. Unplug the front and rear cooling fan power connectors.
8. Plug the power cord into the system unit.
9. Press the power-on switch on the operator panel to turn on the power.
Does the power LED on the operator panel come on and stay on?
NO
YES
Replace the faulty cooling fan. Go to "MAP 410: Repair Checkout" in the
RS/6000 and Eserver pSeries Diagnostics Information for Multiple Bus
Systems.
Exchange the operator panel electronics assembly. Go to "Step 1520-5".
Reinstall the original operator panel electronics assembly. Go to "Step 1520-6".
Go to "MAP 410: Repair Checkout" in the RS/6000 and Eserver pSeries
Diagnostics Information for Multiple Bus Systems.
Go to "Step 1520-7" on page 48.
Go to "Step 1520-8" on page 49.
Chapter 3. Maintenance Analysis Procedures
47