Power down on startup

Napaim

Napaim

Napaim

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29 Sep 2008
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185
Location
Edinburgh
I've recently moved my whole computer into a new case, it has more room for fans and generally looks better. The old one was 6 years old.

The problem I'm having is that after hooking everything up seemingly fine I will press the power button, electricity will flow through the circuits lighting up things here and there and then it's of again. Mobo light remains on like HAL9000 staring up at my with an evil glare, but appart from that that's it. Done. No more.

I can hard power down and up again, then when the mobo light comes on I hit the power switch and exactly the same happens. This happens with different PSUs.

I may have the HDD LED, Power, Reset, BEEP and 2 other LEDs wired wrong, but I've tried multiple combinations and they seem to be in exactly the right place. The fact that it tries to fire up at all seems as to be proof that it's wired correctly. I don't think I've missed anything.

One HDD for now, has SATA + Power
PSU 500W Corsair (can look up the brand if you like, but the same problem happens with the old one which worked)
ASUS 4850HD with the plastic bit of the heatsink torn off.
2x2GiB DDR2 RAM, it should work fine, I've tried it in the yellow and the black positions.
Phenom II 940BE (moved back to stock cooler as the zalman needs to be tied between two galloping horses to detach from the mobo)

I'm at a loss, I'll keep at it and checking back. Hoping I don't have to buy a new MOBO, but if so are there AM3 mobos that work with my processor? If so a recommendation would be just gorgeous.

Thank you my darlings.
 
I took out the GPU, HDD and everything but the power blobbie.
Same problem.

I swapped out the RAM for some good old 800MHz DDR2 and yet again, same problem.

It's looking to me like a mobo problem? If that's the case then I can't a ford a damned new computer if it's going to be 100 for a mobo and 100 for the same RAM I have with a different sticker!
 
Plugged all the PSU power plugs onto the mobo (the big one and probably another 4 or 8 pin one too)? You have used the little spacers between the new case mobo tray and the mobo, right? Before you did the case swap, you weren't by any chance seeing how well you could slide accross nylon carpet whilst wearing a nylon shell suit, were you?*

* Yes I know I've recycled that witty comment from a previous thread, but it seems appropriate to ask:)
 
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There does appear to be a short somewhere. You don't have anything lodged between the motherboard and case tray by any chance?

Next, try each of the pins using manual "touch".. I.e. start the PC by making a contact between the pins, and off again. Try the reset switch etc without using the case panel cables. It's a bit tricky but this will eliminate the mobo or port directly to it.
 
Liampope said:
Plugged all the PSU power plugs onto the mobo (the big one and probably another 4 or 8 pin one too)? You have used the little spacers between the new case mobo tray and the mobo, right?
Click to expand...

I plugged the big one which is next to the little one and the 4 pin one in the corner (the adjoined 2 are called P1 and 24 and come to a total of 24 pins)

I'm not sure what you mean by the spacers/spacer. You mean the area where you're meant to rest it on that you screw it into?
 
Disconnect all the switches and LED's. Then short both power switch terminals with a screwdriver or something metal.

If its still the same, it does sound like something is shorting out somewhere. Are all the lift-off posts fitted for the motherboard?
 
Admiral Huddy said:
There does appear to be a short somewhere. You don't have anything lodged between the motherboard and case tray by any chance?

Next, try each of the pins using manual "touch".. I.e. start the PC by making a contact between the pins, and off again. Try the reset switch etc without using the case panel cables. It's a bit tricky but this will eliminate the mobo or port directly to it.
Click to expand...

I'll tear off the back of the case, there may well be something touching. After that if there are no easier solutions I'll look into touching them up ;)

Does that involve using a live pin and connecting it to the pin-rack at the bottom?

Thanks
 
Napaim said:
I'm not sure what you mean by the spacers/spacer. You mean the area where you're meant to rest it on that you screw it into?
Click to expand...

Yeah - you haven't just screwed the mobo striaght down onto the case have you? You've fitted the little spacers/stand-offs?
 
These...

installing-a-motherboard-01.gif


Fitted...

trager_leer.jpg


Position/number may vary depending on the mobo - e.g. mine uses 9.
 
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Napaim said:
Yeah they're the ones I'm using, not all of them though.
Click to expand...

What do you mean, not all of them? Have you at least used one for each mobo mounting screw? As long as you haven't missed any out and put the screw in anyway and therefore bent the mobo right down onto the tray, you shouldn't have caused a problem. If you missed some or all of these out and have screwed the mobo down onto the tray, many pins/legs/blobs of solder on the back of the mobo will all be shorted out via the case tray. Not good. Fairly common rookie error though :)
 
And I'm right in saying the mobo screws into them and anything toughing the mobo as well as the side of the case is potentially going to cause a short out?
 
Liampope said:
What do you mean, not all of them? Have you at least used one for each mobo mounting screw? As long as you haven't missed any out and put the screw in anyway and therefore bent the mobo right down onto the tray, you shouldn't have caused a problem. If you missed some or all of these out and have screwed the mobo down onto the tray, many pins/legs/blobs of solder on the back of the mobo will all be shorted out via the case tray. Not good. Fairly common rookie error though :)
Click to expand...

This may be what I've done.. I'll take a look, shorting the mobo doesn't tend to destroy it does it? at least I hope not!

Taking the mobo off the case as we speak and doing it "the right way" :)
 
Well I doubt your mobo only has 4 mounting points, but if you only screwed into the spacers you used, you shouldn't have caused a problem. Hard to say though. Make sure the mobo is properly mounted using all its screw holes (9 on my full sized atx mobo) with spacers under each one then try again. If you did screw into holes without spacers that could certainly be the reason you couldn't power up. Mobos/PSUs ought to be clever enough that no damage was caused, but again, hard to say. Take it you never got sparks/bangs/smoke? :) Good luck.

P.S. Are you taking anti-static precautions?
 
Liampope said:
Well I doubt your mobo only has 4 mounting points, but if you only screwed into the spacers you used, you shouldn't have caused a problem. Hard to say though. Make sure the mobo is properly mounted using all its screw holes (9 on my full sized atx mobo) with spacers under each one then try again. If you did screw into holes without spacers that could certainly be the reason you couldn't power up. Mobos/PSUs ought to be clever enough that no damage was caused, but again, hard to say. Take it you never got sparks/bangs/smoke? :) Good luck.

P.S. Are you taking anti-static precautions?
Click to expand...

No static precautions no, and I did screw holes to fit the holder for the custom Zalman fan, do you think that would be a problem?
I took some screenshots. Don't laugh!
Main section: http://imgur.com/nfbMH
Back of case: http://imgur.com/kFiUk
Connected spacer: http://imgur.com/IHSI9

Still workin' on random solutions!
 
Okay well I've given up, replaced entire system into the old mobo and it's fried. Shorts out as soon as you turn it on.

Do all of those spacers need screwed in by any old screw? If so then that's probably the problem, if not then I need a whole new system.
 
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