[ IBM 5160 with IBM 130 watt power supply. ]



So:
* The power supply's fan does not turn when only the hard drive is attached, and
* The power supply's fan does not turn when only the motherboard P9 (+/- 5 volts) connector is attached.

Both of those loads are known to be sufficient on their own to operate the 130 watt power supply in a 5160.


CONCLUSION:  The IBM 130 watt power supply is faulty.