IBM PS/2 90 XP 486 Hardware Maintenance Reference page 41

3.3.4 Motor-Start Jumper
The jumper in position
If the jumper is in place, the hard disk drive motor starts instantly when
you power-on the system.
drive (sequentially).
system with the motor-start jumper in place to reduce POST time.
large-capacity drives are added to the system, and they are set to start
instantly (at power-on), the power supply might shut down.
happens, it means that the total motor start surge current (of a multiple
drive start-up) exceeds the reserve-current capacity of the power supply.
You may have to remove the motor-start jumper from the option drives so
that POST starts them in sequence.
Note: Original Equipment Manufacturer (OEM) drives may have a jumper or a
switch to set the motor-start mode.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Motor-Start Jumper
4 (illustrated above) is the motor-start jumper.
If the jumper is not in place, POST starts the
Some 320MB and 400MB drives are shipped in the
¦ Copyright IBM Corp. 1990, 1992
3.3.4 - 1
If other
If this