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Press the "On" button - nothing happens!

Press the "On" button - nothing happens!

I went away for a few days, left the PC switched off for the duration but when I pressed the "on" button last night when we returned, nothing happened.  It's a 2Gb Intel quadcore on a Gigabyte GA-P35 mo-bo in a tower case with 3 HDDs and 2 DVD drives and a Radeon 9600 series graphics card.

The screen remained in sleep mode, no fan started rotating and as far I can tell nothing else happened. The only thing that did happen was that the illuminated scroll wheel on the USB mouse flashed instead of being continuously on.

I built the kit myself over two years ago, and haven't opened it up for at least three months - it's been fine - so I've no worries about dismantling it and so on.

I need a few hints where to start looking and some diagnostic logic.

The power supply seems favourite at the moment - any tips as how to test it? Where should I putting the multi-meter probe ends?  I'm not sure if I have a compatible one lying around to test by replacement.

Many thanks.  John.

PS: hammer The Mrs isn't happy...

Liverpool: Capital of Culture 2008
Anfield: Capital of Football since 1892
Iechyd da! John
Glannau Mersi, Lloegr.

RE: Press the "On" button - nothing happens!

First try removing all the power to everything except what is essential.  If that doesn't reveal anything (i.e. system still doesn't boot up), then I'd swap power supplies,even if I had to borrow one.  Just to make sure it isn't something else computer-related.  If the other power supply makes the computer work, you know the old one is bad.  If it doesn't, then you know something about the computer failed.  

It is not possible for anyone to acknowledge truth when their salary depends on them not doing it.

RE: Press the "On" button - nothing happens!

Have you tried shorting the jumpers that act as the POWER switch??  That would rule out the power switch itself.

There are power supply testers (the cheap ones are $20), but I only use them to prove power supplies dead NOT to prove them as being good.

I've seen lots of them test good, but then a new power supply fixes the problem, so go figure.

If none of the lights on the tester light up, it's pretty conclusive.

RE: Press the "On" button - nothing happens!

Thanks for the suggestions.  

It looks like back to basics...  So I'll find some time over the weekend and let you know.

Liverpool: Capital of Culture 2008
Anfield: Capital of Football since 1892
Iechyd da! John
Glannau Mersi, Lloegr.

RE: Press the "On" button - nothing happens!

By "back to basics", do you mean back to an abacus since the computer is dead?   Kidding.

RE: Press the "On" button - nothing happens!

You could also do a basic test on the PSU by disconnecting it from everything in the computer.  Take one or two known good, old hard drives which have nothing important on them, and connect up just those, so as to give the PSU some load.  With mains power applied, short out the following connectors:-

20-pin motherboard connector  -  pins 13 and 14
24-pin motherboard connector  -  pins 15 and 16

Does NOT apply to all PSUs, but pins 13 and 15 respectively are usually black, and pins 14 and 16 respectively are often green.

The PSU should now start up.  You can certainly check voltages at the pins but they may not be particularly accurate as some voltage rails won't have a load on them.


RE: Press the "On" button - nothing happens!

Ermm... all is well.

It seems the PC was in some deep coma mode, far beyond just sleeping.

After some 12 hours with the power cable removed, I reconnected it and pressed the "on" button.  The fans started, the POST ran, the mouse wheel went blue and a Win 7 "re-starting Windows" splash appeared.  It took some time but eventually the Welcome screen and log-ins appears, with the Mrs still logged in.

I rebooted and all is well, and I'm posting from it right now.

I think I need to check the Mrs's settings...

Liverpool: Capital of Culture 2008
Anfield: Capital of Football since 1892
Iechyd da! John
Glannau Mersi, Lloegr.

RE: Press the "On" button - nothing happens!

It could be the start of a power problem UNLESS it was in SLEEP or HIBERNATE mode.  There is no such thing as Deep Coma Mode last time I checked.

RE: Press the "On" button - nothing happens!

Blame the Missus, and tell her you've now got to go buy a new computer.  You know, that ultra fast whizzy one you've always wanted. bigsmile


RE: Press the "On" button - nothing happens!


Quote (Ben):

It is not uncommon, that surges cause the PSU to go into protected mode...

unplugging it from the mains, and hitting the power switch (holding it down for more hhan a minute) will usually bring it out of that mode...
That is a distinct possibility.

I've now changed the "hibernate" time to "never", and clearly it was a user error, the user being SWMBO!

Many thanks again for the swift and knowledgeable responses.

Liverpool: Capital of Culture 2008
Anfield: Capital of Football since 1892
Iechyd da! John
Glannau Mersi, Lloegr.

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