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Bantu
09-08-2011, 12:13 PM
Working away happily and the PC stopped. Just as though the power went off.

I assumed it was a dead PSU, so replaced with a new one, still no life in it. Any suggestions.


Been running great for a couple of yrs no problems.

razzarphenix
09-08-2011, 12:26 PM
So does anything light up, with the side panel off first unplug the power supply from the mains, press the power button a few times to drain any residual power, then plug it into the mains, and press the power button does the cpu fan move even a smudge or led lights or anything come on momentarily or is it still dead?

If its still dead and your sure you've plugged the new PSU in correctly (ie both the main 24 pin ATX connector + the seperate 4 pin power "p4" cable is connected then its most likely the motherboard. Are there any bulging caps?

nedkelly
09-08-2011, 12:49 PM
is the wall socket getting any power?

Bantu
09-08-2011, 01:09 PM
Power from wall is fine.

Tried that not a flicker, no sign of any LED's on. All cables are in properly.

Speedy Gonzales
09-08-2011, 01:14 PM
Is this the PC in your sig or another PC?

Bantu
09-08-2011, 01:26 PM
Hi Speedy long time no see. Yes in the sig

dugimodo
09-08-2011, 01:56 PM
power button function properly? not stuck in or something? try disconnecting the switch and shorting the power button pins momentarily on the motherboard or shorting the green and black wires (I think, pay to check this it's been a while for me)on the PSU to force it on . It may not start but fans and drives should spin up at least.

Also check the CMOS battery, ideally pull it out and put a volt meter across it. check for any leakage around it. Do look for bulging caps but I personally dont think that problem is as common as it seems (someone always points it out as the "probable" culprit).

If that fails try removing everthing - hard drives, video card, optical drive etc 1 by 1 and pushing the power button to see if there's any response to try and isolate the culprit. Also chek the CPU fan (prob not the culprit but worth checking) is connected properly and the heatsink firmly attached. Obviously it won't boot without graphics but if a fan starts or something beeps after removing it you can consider it part of the problem.

It's not impossible for a faulty component to prevent the system from starting, if it was a fan though you'd normally get a short pulse of power and an immediate shutdown.

If none of that works the CPU or motherboard has likely failed, shame too it looks like a nice board.

Speedy Gonzales
09-08-2011, 02:04 PM
If youre near Mt Eden, I could check it out

Bantu
09-08-2011, 02:09 PM
From memory there used to be a green led on the motherboard that was on when main power was on, that is out which is starting to make me think possibly motherboard.

With it just shutting down like it did leads me to believe it is not cmos battery. It is just as though power had been shut off at the wall the way it stopped.

Wish I could get another Gigabyte EX38T or X48T but be damned hard to find one now I think.

Bantu
09-08-2011, 02:10 PM
If youre near Mt Eden, I could check it out

Howick speedy, thanks for the offer though.

Speedy Gonzales
09-08-2011, 02:13 PM
You sure you've connected the CPU , ATX 12v connector back in?

Bantu
09-08-2011, 02:57 PM
Yes both connected and firm.

Last few months usb has been a bit dodgy, works sometimes and not others so maybe mboard might have been dying, but we shall soon find out.

Just got a new Mboard and CPU off Ascent so hopefully that will do the job. My memory and graphics should fit it ok.

Will put up with just the laptop and other PC for a couple of days:-(

Bantu
10-08-2011, 01:29 PM
New m/board and CPU in, everything connected, still dead.

Tried using the reset switch as start switch nothing.

Am getting power to the power supply as the fan stat to run then slows and stops. A blue led flashes on on the other fan just for a sec.

Not sure if a memory module would cause this or now. Might have to try just one in and try a couple possibly:-(

1101
10-08-2011, 02:07 PM
asuming youre using the new power supply....
remove everything except ram from the m/b, including all cabling to HD USB switches etc
**especially remove any usb cabling to front of case
If it has onboard graphics use that, else see if you can get another vid card
use a screwdriver to CAREFULLY turn on by shorting the power on pins

you may need to try new ram & vid card, or get them checked

**worst case senriao : power supply fault could have blown old board, old ram, old HD or old vid card
** could be something as simple as a internal (case) usb cable, if your lucky

may seem obvious, but there are 2 power cables that need to connect to motherboard, the big one & another small one (either 4 or 6 pin) ....just in case you missed that 2nd cable :-)

dugimodo
10-08-2011, 02:36 PM
And of course the switch on the PSU is also turned on....

It has to be something common to both setups so as suggested already dissconnect everything you dont need to see if that helps. Also as mentioned previously try it with no graphics just to see if it beeps at you, assuming there is a speaker of some kind on the board or connected to it.

Worse case scenario would actually be a faulty motherboard has blown both the old and new power supply...

Unlikely though as you would probably have seen some indication - smoke, sparks, noise, or something

razzarphenix
10-08-2011, 02:37 PM
asuming youre using the new power supply....
remove everything except ram from the m/b, including all cabling to HD USB switches etc
**especially remove any usb cabling to front of case
If it has onboard graphics use that, else see if you can get another vid card
use a screwdriver to CAREFULLY turn on by shorting the power on pins

you may need to try new ram & vid card, or get them checked

**worst case senriao : power supply fault could have blown old board, old ram, old HD or old vid card
** could be something as simple as a internal (case) usb cable, if your lucky

may seem obvious, but there are 2 power cables that need to connect to motherboard, the big one & another small one (either 4 or 6 pin) ....just in case you missed that 2nd cable :-)

Good advise. Also a short from something on the case is a low possibility (standoff in the wrong place etc..) so if nothing else works a few key points:

Faulty RAM, Faulty CPU or even if both are completely absent wont stop the motherboard turning on (so if it has a LED on the board it will light up, and the power supply fan will be whirring away but the system wont (obviously) post.

So take the board + PSU out of the case, put the board in the motherboard box resting on the foam it was packaged in (if you still have it) otherwise ontop of clean + dry (important) cardboard will be fine.

Remove anything else on the board like RAM + CPU, turn it on, does it stay running or switch back off? If it switches off the board or PSU is faulty if it stays running, turn it off again, and add one piece at a time (starting with the CPU) till it stops working and you've got your culprit.

dugimodo
10-08-2011, 02:49 PM
Also check the power cable or try a different one if you haven't already.
And if you use a multiboard or similar make sure it hasn't tripped it's circuit breaker.

The PSU can be turned on by shorting pins 13 and 14 of the 20 pin connector which should be using green and black wires. If its 24 pin dont count the last 4 (usually detachable) and it goes from 1-10 and 11-20 starting from the orange wired end. 11-20 is on the clip side of the plug. If you get a paperclip or short piece of wire and short these the PSU will fire up, maybe try this on your old PSU to see if it's actually dead with just the power cable and a fan attached.

Bantu
10-08-2011, 03:11 PM
Well took everything out bit y bit and kept trying it.
All cards ot except graphics
HDD's disconnected
Memory our one stick at a time
Then FINALLY took the display card out and everything spun up, cpu, all fans etc.

Soo New Display card ordered. I guess that was the originaly fault prior to purchasing PSU, CPU, Motherboard.

Might get a new case now and put all the old bits in for a spare, less display card.


Thaks guys, help appreciated.

dugimodo
10-08-2011, 03:17 PM
Yeah seems like you have almost purchased a new pc in parts. It's difficult to diagnose faults without spare parts and as you have discovered the hard way guessing and buying bits is hit and miss.

You could always sell of all the extra parts to cover some of your costs, I always have at least 2 PC's myself though :)

Bantu
10-08-2011, 03:54 PM
I have 3 others here plus 3 laptops. but was not pulling the others apart to check, so now i guess an upgrade through trial and error.
Reasonable parts added.
850w PSU Enermax
Gigabyte GV-N460OC-1GI Video Card, GeForce GTX 460, 1024MB, DDR5, PCIe-16
Gigabyte GA-X58A-UD3R Motherboard, Socket 1366, Intel X58
Intel Core i7-960 3.2 GHz, Socket 1366, Retail pack with fan
Plus I already have DDR3 1600 memory * 6Gb