I'm having a lot of problems with my pc now. Right now, it keeps blue
screening when it boots into windows. I've tried reinstalling
windows, but it says setup cannot copy the file:xxx. I've read about
this and it points to memory errors. I've swapped out the memory once
and still have this problem. I've run memtest on my original memory
and sometimes it gives me errors, lots of them, and other times it
runs without any errors. I've tried the install on a new hard drive,
multiple OS disks and a different dvd drive. The only thing I can
think of as being the problem is a bad motherboard or power supply.
Is there a way to test the psu? I don't have a spare to swap it out
with. In my BIOS it says my psu fan speed is about 750 rpm, and it
shows it in red. What's it supposed to be? Does anyone else have
any other things I can try? The pc ran fine for about 2 years, then
it did this once. I took it into a pc repair shop and they said
everything tested OK. When I got it home I was able to reinstall
everything OK. About 2 months later, the same thing happened again.
The fact that my pc keeps blue screening and I can't reinstall
Windows, I'm guessing this is a hardware issue.
The fact that it worked when you got it home, suggests to me that
when they removed some components and reinserted them, it may have
cleaned the contacts and corrected whatever the problem is. I'm not a
big fan of abrasive cleaning methods (like pencil erasers), and
simply reinserting the component into its connector, should clean
it for you. The gold plating on some components is extremely thin,
and can easily be completely removed without too much trouble.
If memtest is giving errors, that isn't acceptable. Memtest is not
really a sensitive test for memory errors, so if you see errors, then
things cannot be very good.
Memory is sensitive to voltage and operating speed, and the timings
you use at that speed. So there are other issues, beside making
bad contact, that can cause perfectly good memory to make errors.
To do maintenance on the computer, make sure all the power is removed.
Turn off at the back, and then unplug it. Pull the memory sticks, and
then reinsert them. Plug in and switch on again.
For memtest, there are a couple versions you can use.
http://www.memtest.org (memtest86+)
http://oca.microsoft.com/en/windiag.asp (microsoft version)
Once you are in Windows, this is a pretty sensitive test of system
stability. This won't identify a particular memory stick, but it
will tell you whether the CPU, Northbridge, and memory sticks, are
all working together error free. This program should run for hours,
without complaint. Using the default settings on my 1GB memory
system, it will use and test about 700MB. It also heats the processor a bit,
as the calculations keep the processor pretty busy. (On my overclock
test machine, this program stops with an error, in a minute or so.
When things are stable again, you should be able to go for four hours
easily.)
http://sp2004.fre3.com/beta/beta2.htm (orthos, based on Prime95 torture test)
There is no point trying reinstalls, when a system is unstable. You
should try to fix the instability first, then reinstall when your
best testing indicates all is well.
PSU fans only spin as fast as is needed to cool the supply. The
BIOS doesn't really know what a decent fan speed is. You could have
a high efficiency (80%+ efficiency) power supply, with a 140mm fan,
and that might only need to spin at 750RPM.
Feel the air coming out of the PSU. Does it feel cool or boiling hot ?
If it is boiling hot, that will reduce the potential life of the
capacitors inside the supply.
Did the fan on the PSU always spin at that speed, or is it spinning
a lot slower than it used to ? Does the PSU have a fan speed
adjustment know (only a few supplies have those) ? Does the fan
make noise, run erratically, or otherwise no longer perform like
new ?
If you look in the BIOS hardware monitor, there may be voltages
listed for the major supply rails. There could be 3.3V, 5V, and
12V measured in there. You don't want the voltages to be off my
more than 5% of nominal. On the 12V rail, below 11.4V would be
too low. A bit less than that, and some disk drives start to
complain.
The BIOS hardware monitor is not that accurate. If the hardware
monitor measured values leave any doubt in your mind, then you
find a multimeter, switch to DC volts, use a 20V scale perhaps,
and measure the rails by poking the backside of the main
ATX power connector. You can clip the ground lead of the
multimeter to a shiny piece of metal on the computer chassis,
such as a screw on an I/O connector. Then you'll only
have one probe from the multimeter to manipulate, to make your
readings. Use the volts/ohms holes on the multimeter, for your
measurements, and not the current hole. Some meters have more than
two holes on the front, for the test leads.
HTH,
Paul