problems after power surge

  • Thread starter Thread starter petesouthwest
  • Start date Start date
P

petesouthwest

A non techy mate's pc 'stopped' working after a power surge at his
home, he asked me to have a look as it would not boot without hanging
and could not enter BIOS.

He brought it round to my place and plugged it into my kvm switch, it
booted enough for me to initiate a scandisk which revealed: "first
allocation unit is not valid" errors. Scandisk fixed these. I then run
the machine, rebooted etc on and off for 24 hours with no problems. I
checked it with his mouse and keyboard, and other than an apparent
fault with the 'del' key not working (hence could not get into
BIOS) it seemed fine. Apparently fixed I gave it back.

When he got it home he said 'it was the same as before' still had
errors and he had had to turn it off at the plug. He brought it round
to mine where, once again I connected it to a kvm switch, turned it on,
allowed it to go through its disk check (its FAT32 so it would scan
after a switch off at the mains) where it found one "first allocation
unit is not valid" error and then worked fine. He took it back only to
bring it straight back saying that he was getting a message 'no
support' and a press F1 keyboard error. I tried it with a different
keyboard but get the same error message. Seemingly the keyboard
controller on the motherboard has decided to die.

That still leaves me wondering where exactly the fault is,what caused
it and whether I should recommend a whole new pc, new motherboard,
motherboard and PSU or what?

Any ideas?

Pete
 
A non techy mate's pc 'stopped' working after a power surge round
to mine where, once again I connected it to a kvm switch, turned
it on, allowed it to go through its disk check (its FAT32 so it
would scan after a switch off at the mains)
Click to expand...

I guess you mean Windows 9x. Generally, shutting down through
Windows is better than switching it off. You can press a key at
start up to do the scan disk.
where it found one "first allocation unit is not valid" error
Click to expand...

Does your friend have a removable media copy of any important files?
If not, stop what you're doing and take care of that first (think
USB flash drive).
 
John said:
I guess you mean Windows 9x. Generally, shutting down through
Windows is better than switching it off. You can press a key at
start up to do the scan disk.
Click to expand...
no its Windows XP Home..............
 
petesouthwest said:
no its Windows XP Home..............
Click to expand...

I think you can go to a DOS prompt and use CHKDSK.

Again, make sure any important files are backed up whenever you mess
with stuff.
 
The boot cd looks interesting, but I cant actually see the link to
download the iso?
Click to expand...
The links have probably been disabled as it consists mostly of pirated
software.
 
A non techy mate's pc 'stopped' working after a power surge at his
home, he asked me to have a look as it would not boot without hanging
and could not enter BIOS.

He brought it round to my place and plugged it into my kvm switch, it
booted enough for me to initiate a scandisk which revealed: "first
allocation unit is not valid" errors. Scandisk fixed these. I then run
the machine, rebooted etc on and off for 24 hours with no problems. I
checked it with his mouse and keyboard, and other than an apparent
fault with the 'del' key not working (hence could not get into
BIOS) it seemed fine. Apparently fixed I gave it back.

When he got it home he said 'it was the same as before' still had
errors and he had had to turn it off at the plug. He brought it round
to mine where, once again I connected it to a kvm switch, turned it
on, allowed it to go through its disk check (its FAT32 so it would
scan after a switch off at the mains) where it found one "first
allocation unit is not valid" error and then worked fine. He took it
back only to bring it straight back saying that he was getting a
message 'no support' and a press F1 keyboard error. I tried it with a
different keyboard but get the same error message. Seemingly the
keyboard controller on the motherboard has decided to die.
Click to expand...
That still leaves me wondering where exactly the fault is,what
caused it and whether I should recommend a whole new pc,
Click to expand...

That would certainly fix the problem.
new motherboard, motherboard and PSU or what?
Click to expand...

Its never possible to say definitively with a system thats been
zapped by a power surge. That usually kills the PSU first, but
not always, and even if you say swap the PSU and it appears
to work, you may see another fault show up relatively soon etc.

Its quite likely that the PSU isnt putting out the full rail voltages
anymore or you've got too much hum on say the 3.3V rail and
that can certainly produce those variable symptoms, particularly
if his mains voltage isnt the same as yours.

Trouble is that you can waste your money if you say swap the
PSU and it works for a while, swap the motherboard when it
stops again, and then find that the hard drive is damaged too
by the over voltage that the PSU produced when it got zapped.
So you would waste considerable money over going for a new system.

But obviously if its only affected the PSU you will
be a lot better off financially by just replacing that.

There is no way to be sure with a system zapped by a mains glitch.
Any ideas?
Click to expand...

I'd personally go the PSU route, but then I have spares lying
around and its just a nuisance if swapping that doesnt fix it
for long. And I can test the PSU to see if the rail voltages
are fine and if its got noise on the rails too.

If you do replace the PSU and it appears to be fine, I'd
certainly run the hard drive manufacturer's diagnostic on
the drive before assuming its fine, and of course back up
what he'll slash his wrists if he loses if that hasnt happened
yet, even if I had to run out and buy a DVD burner to do that.
 
Back
Top