From: Ian on

"Paul" <nospam(a)needed.com> wrote in message news:fmi5lq$mlr$1(a)aioe.org...
> Ian wrote:
>
>>
>> Paul
>>
>> Absolutely brilliant! You have given me some really good info which I am
>> going to follow up on.
>>
>> I will not have access to the machine for a few days yet to experiment.
>> If I do as you say (holding pin to ground) will the XP still be able to
>> shut down the machine, or will I need to mount an external switch to
>> disable the mod to power down?
>>
>> Ian
>>
>
> I've not tried it. I don't know if you'll be greeted by a
> "it is safe to turn off the machine" screen with the power still on,
> or Windows will blank the screen. I presume pressing reset
> will start things again.
>
> Paul
>


From: Ian on

"Paul" <nospam(a)needed.com> wrote in message news:fmi5lq$mlr$1(a)aioe.org...
> Ian wrote:
>
>>
>> Paul
>>
>> Absolutely brilliant! You have given me some really good info which I am
>> going to follow up on.
>>
>> I will not have access to the machine for a few days yet to experiment.
>> If I do as you say (holding pin to ground) will the XP still be able to
>> shut down the machine, or will I need to mount an external switch to
>> disable the mod to power down?
>>
>> Ian
>>
>
> I've not tried it. I don't know if you'll be greeted by a
> "it is safe to turn off the machine" screen with the power still on,
> or Windows will blank the screen. I presume pressing reset
> will start things again.
>
> Paul
>

Paul

The friend I am helping to fix his PC brought it back to my home and I set
the machine up again. After unloading it from his car (200 mile journey) it
worked impeccably for several hours (whilst he had it back at his home it
still exhibited the fault). Eventually I removed the board to check for the
squashed solder pad. It was present but not quite shorting so was not the
cause of the shutdown problem.

What I did see on the back of the board was lots of damaged track! The board
which came from eBay (HK) had been abused and some tracks had already been
repaired. I repaired one broken track and reassembled the system.

The machine boots and runs XP but still randomly switches itself off
instantly. I then tried the PS_ON# grounding link but unfortunately it's
not the answer I hoped for! The machine still switches itself off instantly
(so losing any data etc) but the PSU and fans stay powered up until I open
the link.

So its back to square one. The machine is used for video editing and has
some expensive professional (but now 'legacy') video processing hardware
which when it was introduced would only run an a limited range of tested and
'approved motherboards. When originally purchased the system had a Tyan
Thunder board but about 4 years ago was upgraded with P4C800 and was running
fine until it refused to switch on one day. The P4C800 was found to be
faulty (not by me) so the P4C800 Deluxe that is now causing the problem was
bought on eBay.

I am now looking for another board on the short list. ASUS, or possibly an
Intel D850DMV or Supermicro X6DA8

Anyway, thanks to everyone who responded, I am really impressed with the
level of expertise that's just a few keystrokes away.

Ian