Dead motherboard?

[dugimodo]

One of my older PCs just stopped working. It'll boot up briefly if you leave it powered off at the wall for a while first, but you don't get time to test anything before the display goes blank and the PC becomes unresponsive.
also the CPU and case fans alternate between flat out and slow spinning, the case fan actually stops completely and this fan behaviour is a repeating pattern. Swapping the fans just swaps the behaviour.

When it's like this the power and reset buttons do nothing and the hard drive light is off. If I force it off with the PSU button it will not boot at all.
I tried going into the BIOS and checking CPU temps - low 20s and after a minute the PC did the same thing so it's not an OS problem.

I've tried:
CMOS reset
Disconnected all drives
Booting linux (didn't work at all)

I'm going to pull it apart on the weekend and try a different PSU and maybe different RAM but at this point I'm fairly certain the motherboard has carked it. Any suggestions?
Hard to find a cheap LGA1155 motherboard so I may just have to scrap it and sell whatever parts still work.

Specs
Asrock B75M-ITX
2 x 4GB DDR3 1600
i5 3470

Also 300W SFF silverstone PSU - about a year old and a lot newer than the rest.

[wainuitech]

Change the Power Supply first. Then the memory.

My own Office PC decided to play silly buggers a last week with graphics, thought it may be the board as the PCI-E port went dead as well, even tried a different card, left it over night turned off and the following day it went fine (for a day), then on Monday it finally spat the dummy, no graphics, no POST, checked everything and all fine .

Plugged in a Older testing PSU, and away it went. Then installed a New PSU and its been 100% ever since and is noticeably running better.

Also 300W SFF silverstone PSU - about a year old and a lot newer than the rest.

If its only just over a year its still within warranty, Depending on the model they come with 2-5 Year.

[piroska]

Change the Power Supply first..

+1


This

[dugimodo]

Tried the PSU and then Tried each RAM stick individually, no change. In fact I think it's got worse and no longer even tries to boot or POST.
Also removed a PCI-E SATA controller I was using for extra hard drive connections. About all that's left is a CPU swap and I'm not sure that's worth the effort.

I do have another of these machines with the same motherboard and CPU so in theory I could swap it out, but that means dismantling 2 PCs for a unlikely shot in the dark.
I think maybe selling the CPU & RAM might be the best option, but then I suppose I have to swap the CPUs to make sure it's ok to sell anyway lol. I had a look for cheap 1155 boards but not much joy there.

[piroska]

Tried the PSU and then Tried each RAM stick individually, no change. In fact I think it's got worse and no longer even tries to boot or POST.
.

Ok, it's the motherboard.

UNless you can find one of the same specs, it's a MB, CPU change all at once....

[apsattv]

I have a similar problem on the spare pc the neice and nephew play their games on. Won't power on. mb light remains lit. give it a few mins switches on eventually. Did some trouble shooting on it. Pulled out the power supply and sat it on the table. Powered pc on, p/s making tick noise and ps fan making tiny movements trying to fire up. Came on eventually. Then I ran CpuID hw monitor which showed
3.3 v is 3.28 (fine)
+5 v is 4.8 (fine)
+12v however is all over the place 3 , 5, 8, 11 etc etc

pc however is stable even a 4 hours stress test didnt shut it down.
ps is a 450 watt coolermaster about 7 or 8 years old.

[dugimodo]

Yours sounds like a PSU issue, maybe the fan is faulty and replacing it might work, but up to you if it's worth trying that.

Gave up on mine and dismantled it, will list the CPU and RAM on trademe after I test them and make sure they are ok.
Trouble is the whole PC only cost me $150 off trademe and the seller regularly lists the same machines at that price so the cheapest option to repair it is actually to buy a whole other machine.
I have too many anyway, this just leaves me with 4 one of which I'm currently trying to sell.

Sometimes I think I should just buy a decent laptop and just have that and my gaming PC, but playing around with these things is my hobby

[apsattv]

Yep my best option scrounge another p/s from somewhere. Pc is an old core 2 duo , so not worth spending on.

[wainuitech]

Often I get motherboards from Aliexpress. esp if a person doesn't have the money to buy new hardware. Sure most are second hand, but there is warranties on them still. No real difference than buying on trademe second hand. Most are laptop Boards, and one of my own I brought for socket 1155, runs perfectly fine. Only ever had one dud, but that soon got sorted.

Just looked there are plenty of 1155 boards, generally with postage around the $70 area.

[dugimodo]

I'll have a look, already tried Ebay and Amazon but nothing really looked that good of an option