PSU problem causing windows\system32\config\system is missing or corrupt in windows XP

[dk]

Hi,

Built a pc for a friend, Athlon 1700+, 128mb, Asrock MB, 60GB HD, 8mb S3
graphics card, Windows XP Profesional. The system ran well for 6 months then
windows gave the error as per subject. Followed the instructions on Windows
support and recovered the OS.

A couple of days later he said the scan disk would run every time he started
the pc even tho it was always shutdown properly, then the above error
happened again.

I have ruled out virus, software problems etc, and scanning the HD has not
shown any problems, however the floppy drive has been giving read errors
with disks that I know work on other systems.

Anyway looking in the BIOS I notice the power readings are slightly low:

+12v is alternating between 11.77 and 11.90
+5v is alternating between 4.78
+3.30v is alsternating between 3.26 and 3.28

VCore is 1.70-1.71

Is this normal or could it be causing the symptoms above.

Just as I`m about to send this I now find the ON/OFF switch on the front of
the case will not power up the PC even tho the power LED is on, I have to
try several times, maybe it`s looking like the PSU is the problem.

Any help would be much appreciated.

 

[AndrewJ]

A couple of days later he said the scan disk would run every time he started
the pc even tho it was always shutdown properly, then the above error
happened again.

I believe the HDD is flakey. Big drives are so cheap and fast now, I
would updrade the drive. That one might be ok for storage as a second
drive but be careful.

 

[fj]

Design tolerances for PSU, Motherboard, etc are +/- 5% => all your voltages
are within tolerance.

Hi,

Built a pc for a friend, Athlon 1700+, 128mb, Asrock MB, 60GB HD, 8mb S3
graphics card, Windows XP Profesional. The system ran well for 6 months
then windows gave the error as per subject. Followed the instructions on
Windows support and recovered the OS.

A couple of days later he said the scan disk would run every time he
started the pc even tho it was always shutdown properly, then the above
error happened again.

I have ruled out virus, software problems etc, and scanning the HD has not
shown any problems, however the floppy drive has been giving read errors
with disks that I know work on other systems.

Have you tried using chkdsk /r? I've found times when chkdsk /f doesn't
show a problem, but chkdsk does fix a disk problem.

While the issue with the floppy disks might be related, probably not. It's
not unknown for floppies to be not readable from system to system.

 

[w_tom]

If motherboard monitor was not calibrated with a 3.5 digit
multimeter, then you don't know what voltages really are. As
posted, +5 volts is a problem. But again, we don't know
without meter readings. All voltages must appear in upper 3/4
limits of the chart provided in previous discussions:
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
http://tinyurl.com/2t69q and
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

Based upon information as currently provided, any answer you
get is only wild speculation. You must provide numbers and
other specific facts. Without numbers, well, that power
supply could have been defective for the past 6 months.
Resilience built inside other components may have simply
masked a power supply defect. Again, we don't know until
first we have accurate numbers. And again, that 5 volt
number, if accurate, suggests a problem.

A power supply 'system' contains multiple components. Which
one might be defective? Again, that meter should provide
useful information especially when taking numbers during the
first two seconds after power on switch is pressed. Even if
you don't understand what was observed, that information means
other knowledgeable posters can provide more than just wild
speculation. Get the meter. Get those essential numbers.