IBM 6150 Hardware Maintenance Manual page 167

TNL SN32-9004 (August 87) to 75X0152 or 75X0166
Step 8
One of the optioris or adapters you removed is failing.
3-0060-8 Service Manual
1. Set the power switch on the system unit to Off.
2. Install one of the removed options or adapters. Use the following
order, slots C, D, B, then the adapters in the other slots, being sure
that the fixed-disk and diskette drive adapter is the last adapter
installed.
3. Set the power switch on the system unit to On and wait 2 minutes,
then answer the following question.
IS "23" DISPLAYED IN THE TWO-DIGIT DISPLAY?
YES Repeat the above steps.
NO The last option or adapter installed or a FRU attached to it is
failing. Use the removal and replacement procedures in the
section that applies to the FRU and exchange it. Go to "Step
25" on page 3-0060-26.