IBM H Series Installation And Service Manual page 65

If the symptom did not change and all FRUs have been exchanged go to
"Step 1520-14" on page 2-31.
If the symptom changed, check for loose cards, cables, and obvious prob-
lems. If you do not find a problem, return to "Step 1540-1" on page 2-38
and follow the instructions for the new symptom.
Step 1520-14
The problem lies within the system unit hardware or with the line voltage/wiring.
Shut the system down, turn off the system, and remove the power cable(s) from the
power supplies.
Exchange the following FRUs in order. If the I/O board is to be replaced, see notes
on 2-1
1. Power Cables to I/O Board
2. I/O Board
3. Power Distribution Board
4. Service Processor (Model H50)
Restart the system and perform Error Log Analysis.
Do you get an SRN indicating a Voltage Sensor is out of range?
NO The last FRU exchanged is defective. Go to "MAP 410: Repair Checkout"
in the Diagnostic Information for Multiple Bus Systems.
YES Reinstall the original FRU.
Repeat the FRU replacement steps until a defective FRU is identified or
all the FRUs have been exchanged.
If the symptom did not change and all FRUs have been exchanged go to
"Step 1520-12" on page 2-30.
If the symptom changed, check for loose cards, cables, and obvious prob-
lems. If you do not find a problem, return to "Step 1540-1" on page 2-38
and follow the instructions for the new symptom.
Chapter 2. Maintenance Analysis Procedures
2-31