Completely dead PC - Help!

Kangaxx

Kangaxx

Kangaxx

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I have been having lots of problems with my current build, and have run out of ideas to get it working again. But first, a bit of history...

The system was built about a year ago (AMD Phenom 2 X3 on Gigabyte mobo with 4GB of Corsair RAM), and worked fine from day one. In April this year, I noticed some weird things going on in windows, such as USB devices disconnecting and then reconnecting by themselves. I didn't think much of it. Then one day at the start of May, the system simply would not power on. No POST, no beeps, nothing. It was completely dead.

I went through the usual procedure of cleaning it all out, removing extraneous drives, cards etc. but nothing worked. I first replaced the PSU with a modular OcUK one, but that still did not fix the issue. I then obtained an RMA from gigabyte for the mobo, and sent it back to them. They sent it back with an updated BIOS, saying it was now working. It wasn't. So, I sent it back again, and they sent me 8 pictures of the board working in their lab, thus proving the mobo was working fine.

Now I was getting puzzled at this stage. When i got the board back i did an open install, with no chassis, on an antistatic mat to see if it was a short in my chassis. All i plugged into the board was the new PSU, CPU, 1 DIMM and a switch to power the board on. Even this yielded nothing. I swapped out the DIMM and tried the other one, and that didn't work either.

Now looking like there was only one thing left to try, I obtained an RMA for my CPU with AMD, and sent it back for testing, but guess what? They have sent it back, saying it was working fine.

The only thing left is possibly the RAM, but I would be shocked if both had died at the same time. The system has not been overclcoked, everything was running stock speeds, and temps have all been fine, so I can't see it being related to that either.

Does anyone have any ideas or suggestions?

Thanks for your time.
 
Are the fans spinning then stopping? Do you have all the 12V connections attached, 20/24 pin and 8/4 pin to CPU? Can you test the PSU output voltages? Have you tried one stick of ram in both or each slot? Can you test the ram in another board, friends etc?

Please list components,

regards, andy.
 
Ok..

Motherboard is GA-MA770T-UD3, with latest Gigabyte BIOS.
CPU is AMD Phenom 2 X3 7200, at stock speeds.
RAM is Corsair 2x 2GB matched pair DIMMs (I don't know the model off the top of my head, and I am at work atm).

I can't test the memory in anyone else's machine. I may have to bite the bullet and buy some more and hope for the best.

The 12V connections are all there, and nothing starts at all. No fans, nothing. Even the PSU fan doesn't start, which is why i tried the PSU and Mobo first.

I know the PSU's both work, as I have tried my water cooling ATX loop back connector, which starts the PSU with no motherboard, and they both work fine, and have confirmed with fans running off the molex connectors.

Thanks for the help so far!
 
I had a similar problem to this - the power supply was not firing up properly due to a duff switch. I dont remember the exact pin numbers but I bridged 2 out with a piece of wire to emulate the switch - and hey presto, everything fired into life.
But you say that power is there already so it must be something else i guess

Edit: If the PSU fan is not working then I would assume it is not switching in properly - I would try the wire trick
 
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scotty365 said:
I had a similar problem to this - the power supply was not firing up properly due to a duff switch. I dont remember the exact pin numbers but I bridged 2 out with a piece of wire to emulate the switch - and hey presto, everything fired into life.
But you say that power is there already so it must be something else i guess

Edit: If the PSU fan is not working then I would assume it is not switching in properly - I would try the wire trick
Click to expand...

I have a doohicky for tricking the PSU into thinking its powered on, which I got with some innovatek watercooling equipment an age ago. I have used this on both of the PSU's I have now, and the fan starts up and supplies power to all the molex's, on both. When you plug the ATX connector into the motherboard, you just get nothing. I was thinking along the same lines, that the board is, for whatever reason, not switching the power state. The only problem with this theory is that Gigabyte have sent me pictures of the board all plugged in and working fine :confused: I will try bridging the wire and see what happens..

I have applied for an RMA on the RAM (Corsair Dominator TwinX 1600 DDR3) and will see what they say. Its the only thing I haven't changed or tested yet!

Thanks for the replies guys. Any further comments are very much appreciated!
 
This is proving troublesome. If you want to bridge the power pins you can use a flathead screwdriver for a second. If this allows the system to power on, it could be the polarity of the header cables or a faulty case switch.

It could be the RAM but i'm surprised you didn't try powering the system on by bridging the power pins whilst it was out of the case.

Hope this helps and you get the system running soon
 
honosuseri said:
Very true tealc, which is why i commented on the polarity, some mobos can be fussy about it
Click to expand...

Right, I pulled apart a spare Molex extender to yield a piece of cable to bridge the 2 pins (Green and black on the front row, near the middle.) I did this and put both RAM sticks in with CPU and Cooler, and plugged everything into the board.

Good news is, it did power on, but the bad news is, not properly. The fan span up on the CPU cooler, but that was it. I next put in my GFX and tried again, and this too powered on, but stayed in a non functional state (in other words, the fan started on it, but the board itself still wasn't working).

I butchered another switch from an old case, and tried that, and the board would not fully power on, or power off the fans while they were running. I am guessing this is because the pins were shorted on the PSU connector, meaning the board will be getting power, no matter what state the switch is in.

But, it still looks like the board is not switching to a "power on" state. As i said earlier, Gigabyte managed to get this working fine using the ATX supply on the board, so I am puzzled as to why I can't. The more I think about it, the more I am thinking the problem is still with the motherboard, as it seems to not be switching to a power on state.

I have ordered a new chassis from ocuk, which I will be getting on Sat, and will put all the stuff into that and try again, just to be sure that the switch I am using is good. My hopes are not high, and I feel I will be struggling through many a long e-mail with gigabyte in order to get this sorted out :rolleyes:

Any more ideas?

Thanks in advance!
 
I would place the board on a box (one it came with is ideal).

Have the gfx card, one RAM stick in and put all power connectors in. I dont mean to patronise you but some people forget the additional 4 or 8 pin connectors.

Use a small flathead screwdriver and touch it against the two power pins for a second to emulate the switch. This should power on the mobo. I'm not clear what you were doing with the wires and bridging the psu connector.

Try this and post back. It could be an intermittent fault on the mobo, if this is the case the manufacturer was lucky when they tested it.
 
honosuseri said:
I would place the board on a box (one it came with is ideal).

Have the gfx card, one RAM stick in and put all power connectors in. I dont mean to patronise you but some people forget the additional 4 or 8 pin connectors.

Use a small flathead screwdriver and touch it against the two power pins for a second to emulate the switch. This should power on the mobo. I'm not clear what you were doing with the wires and bridging the psu connector.

Try this and post back. It could be an intermittent fault on the mobo, if this is the case the manufacturer was lucky when they tested it.
Click to expand...

Its ALIIIVE!

Removed the switch I had got from the old chassis, and removed the shorting wire from the ATX plug, and tried the system again, using your method, and the system beeped and powered on properly. So, at least for the time being, it is fixed. I will have to wait until Sat when my Antec 300 turns up, and I will install it in there, and try again. It should work... but I still can't see why the switch I was using from an old chassis didn't work. If the board doesn't want to work with switches, I guess i could always power it on using a screwdriver ;)

Thanks all for your help. I will post back on Sat about whether it all works in the new chassis.
 
Just a note speaking from bitter experience.. I would be very wary about using the screwdriver method until Saturday. It's a great way to rule out the switch once, but doing it everytime you start the PC is asking for trouble. As a system builder I have many times adopted the attitude, "That will never happen to me" and then bang - there goes the motherboard :(

There are also plenty of other pins really close that you could short acidently so just take maximum care until you get your shiny Antec :)
 
Tealc said:
Just put the PC to sleep and you won't need to press the power button until the new case arrives.
Click to expand...

As the system is in pieces, I will leave it until the new chassis arrives. Seems pointless putting it all together in my old chassis, only to re-build again on Saturday.

I have managed without the PC for the better part of 3 months, I can wait a few more days!

Thanks again for all the help!
 
Happy to help fella. It may be the polarity that you had mixed up (+ and -). Some mobos can be fussy. Start by just connecting the power button to the header and see what happens if no joy flip it around. Then when it will boot you can worry about the additional HDD, reset connectors etc etc.

It may indeed be a faulty switch but should this happen with the new chassis you have something to try. I'm not on call sat it's my b'day ;)
 
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Oh just a thought. As this board is proving to be a fussy tart, it might be worth using washers between the mobo and the heads of the lil screws. I like to use them on all builds, they aren't easy to find in shops but luckily are easy to make.

If you have a hole punch, find a mag with a thick glossy front cover (an old pcformat lets say) and punch the hell out of the cover. Those lil circles that you collect will be the washers. Punch a lil hole in the middle with a skewer or needle and hey presto!

Good luck with the build
 
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