No power off

[stevo1210]

My friend has a PC that has one of the strangest issues I've ever seen. He called me over today to have a look and I was basically stumped. Basically you can't turn it off whatsoever. This only happened about a month or two ago after he removed the PSU to clean it since it was clogged with dust. Once he put the PSU back in it wouldn't turn off.... meaning when you used windows shutdown, it would turn off then about 3 seconds after it would turn back on by itself. Changing to a new Delta PSU made no difference at all... so I can rule the PSU out.

All options such as wake on LAN, wake on ring/PME is set to disabled or off. After power failure or whatever ist's called is also set to *stay off*.

The motherboard is an Intel genuine desktop board with an 865 chipset and the CPU is an Intel Pentium 4 2.4GHz.

I'm stumped. I think it's a hard ware issue since we even went through the effort of re-installing Windows 7 with XP etc. and that didn't change anything!

Thanks.

[PCBONEZ]

Re: No power off

Either has Nichicon HM or has 85C 4&5mm caps and one of them is a partial short [leaky].

.

[seanc]

Re: No power off

I know someone with a Gigabyte board that does this too - 8iG1000MK so I think it's even the same/similar chipset.

There was nothing obviously wrong when I looked at it, I think the person just leaves it on.

If it comes back I'll replace the board in it.

[c_hegge]

Re: No power off

Definately sounds like there's some issue with the motherboard. Exactly what, though, is hard to say. It could be the caps, like PCBONEZ suggested, or it could be something else.

[ratdude747]

Re: No power off

shorted green pwr on wire... something might have fallen in there...

all of the standoffs are the correct length? you could be shorting in that way as well.

[PCBONEZ]

Re: No power off

I have two 8iG1000MK in stock and they don't do that.
One did have HM and I think both had crap for 4 & 5 mm caps.

As I said, odds are there is a leaky or partially shorted cap [probably 4 or 5 mm] that is pulling down some voltage effectively faking and locking in a WOL signal, WOR signal, or a pushed power button.
Might also be in the 'green wire' circuit but the effect is the same.

The delay is because the cap isn't totally shorted yet.

.

[seanc]

Re: No power off

Oh don't get me wrong PCBONEZ, this is one 8iG1000MK out of 60 or so that have been out on rental.

Some blew their Nichion HM caps, others have Rubycon and are fine, then there's this one that has a power-off/on issue.
It's been at least a year since the problem was reported and I would have had the machine back if it had become a bigger problem.

[everell]

Re: No power off

A friend had a computer that would run for a while, then reboot, randomly.

Took a while to figure it out, but it turned out to be a bad reset button.

In your case it might be the power-on button. Try turning the computer on, then unplug the power on button from the mobo, then shut down with windows and see if that fixes it.

[PCBONEZ]

Re: No power off

Oh don't get me wrong PCBONEZ, this is one 8iG1000MK out of 60 or so that have been out on rental.

Some blew their Nichion HM caps, others have Rubycon and are fine, then there's this one that has a power-off/on issue.
It's been at least a year since the problem was reported and I would have had the machine back if it had become a bigger problem.

I actually still have my notes on the 8iG1000MK
One had all KZG in VRM and MBZ for the scattered 1000uF.
Other had mixed HM and MBZ in VRM and HM for the scattered 1000uF.
Then the little 100 & 22 uF were a mix of G-Luxon, GSC, and Swcon.

Wanna bet your buggy board has GSC there?

.

[seanc]

Re: No power off

You can bet.... If I see the PC again, I'll let you know.
Just remembered that a couple of the boards have baked a Rubycon below the AGP slot.

Apart from that, they're nice boards.