At 06:44 AM 05/20/2000 , you wrote:
>My son-in-law's computer, a Compaq Presario 4550, has problems with a
>himem.sys alert on reboot and the system freezes. I suspect that the power
>supply is the problem and I want to test the lead that is used by the power
>supply for the hard drive. I have previously replaced the power supply fan
>and used a Y power cable to run both the fan and another device because the
>mother board connection for the fan was broken.
>
>I have a volt meter. If I put one probe of the volt meter into the socket
>hole that goes to a red wire, and the other probe into the socket hole that
>goes to the adjacent black wire (and the same for the yellow wire and the
>adjacent black wire) will this give me the voltage readings that I want?
>
>I don't want to short circuit the power supply (which may be on its last
>legs), but I do want to test it before replacing it. Is this the correct
>procedure?
>
>If anyone has an "Oh my god!" reaction to what I propose to do, please let
>me know.


Certainly you can test these wires with a volt meter.   Here is something
from a recent question I answered that may be of some help:
====================================================

There are four wires on every connector for hard drives coming from
the power supply.   The Yellow wire is 12v and the black wire next to
it is the ground for 12v.  The red wire is 5v and the black wire next to
it is the ground for 5v.

        ______________
      /                             \
      |   0     0    0     0   |
      --------------------------
     red  black  black yellow

     +5v  -5v     -12v    +12v

I hope this helps.

      Bob Wright
The NOSPIN Group

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