[SOLVED] Computer turn off after few minutes. Tried everything still doesn't work.

[Apcoolboy]

Hello all,

My pc is quite old (around 5 yrs) but I dusting regularly. I encounter weird problem since last 3 days. After I booting up my pc, it suddenly turn off after few minutes. Then I turn it on after 1-2 min, again It turn off. (quicker this time like it might heated up).

As I suspect it might be because of cpu gets hot, I first remove all components (hdd, gpu, psu and others) and also remove cpu fan. Then applied coolermaster V1 IC thermal paste (which is 2yr old but stored properly with cap on). Then connects all components/cables back and starts pc. It works like a charm, for just one day. Again same problem occur.

This time I changed thermal paste again. And as I already changed thermal paste so there might be other things that fails. So I tried to turn on computer with removing components one by one. Removed RAM, graphic card, hard drives. Nothing on mobo (Gigabyte 970a-ds3) . Only CMOS battery and cpu fan. And tried pc turn on. And it shut down after few minutes. Also tried nothing on mobo not even CMOS battery and front panel connectors and tried mobo on with jump pin method yet it shutdown after few minutes. So now its already narrowed down things that might failed.

First I thought it is faulty PSU (which is coolermaster Thunder 500w, old as pc) so I tried turning on only PSU with connecting green ground wire with black wire (found somewhere on forum) and it starts normally. I keep PSU on for 1 hr and it remain on, never stopped automatically as my pc encounter.

Now it may be fault with mobo. Or may be cpu heat up. So I again connects all components and turn it on. Gets into BIOS and constantly check cpu temperature at where my pc gets off. And It never goes beyond 40-43 degree Celsius when it get off. It turn off in BIOS too so no fault with OS.

I am confused between what causes problem, is it PSU or MOBO? I am quite certain problem is with something heating. Because every second time when I tried pc on it turn off quickly like something is still hot to work in normal condition. Also that problem is with psu or mobo as pc keeps shutting down with these two on. Before I change PSU I need to assure it is not faulty (also I have no point to believe that PSU is failing as it remains turn on when I tried keep it on alone).

Also can 2yr old thermal paste causes problem like this? (but cpu is not getting hot beyond 42 Celsius). And if problem is with heating then what else could be heating up on mobo except cpu?

Anything that I would try?
Thanks in advance.

Mobo: Gigabyte 970a-ds3
Cpu: fx 6100
Gpu: Amd radeon hd 6670 1gb gddr5
Ram: 4gb x 2 ddr3 corsair vengeance (total 8 gb)
Hard drives: 1tb WD green hhd, 1tb seagate barracuda
Psu: coolermaster Thunder 500w
Fans: 1 stock cpu fan. 1 front 120mm fan. 1 back coolermaster 120nm fan

 

[doolittle]

Sounds like the PSU works good with no load (paperclip) but cannot deliver proper power once load is placed on it and a protection is kicking in and shutting it down.

Will be extremely difficult to test without swapping out with another known working system to confirm, or have expensive gear (or a gamut of electronics to build test circuits) to do load testing...

 

[Apcoolboy]

Sounds like the PSU works good with no load (paperclip) but cannot deliver proper power once load is placed on it and a protection is kicking in and shutting it down.

Will be extremely difficult to test without swapping out with another known working system to confirm, or have expensive gear (or a gamut of electronics to build test circuits) to do load testing...

Hey thanks for the response.

Just tried another working PSU and same problem. Also went to local repair shop and technician at there told me that something named heat sink on mobo is heating up. Also told me that there is no any option other than changing mobo. I am not expert at repairing thing but I think it can be repaired. Thing that is heating up has written big font "GIGABYTE" on it. If you just look any gigabyte mobo there would be one (as I tried uploading photo here but it fails)

What can I do?

Thanks in advance.

 

[doolittle]

Great, that narrows it down - and also had a similar situation with an old gigabyte board with an X2, the southbridge overheated so I repasted but now it only will boot from USB or SD card using a floppy interface card reader, none of the sata ports will recognize any drives. Linux or nothing on that one now lol - it's worth a shot to maybe save the board, go for it!

 

[ConanLock]

I think it would be worth taking the thermal paste off everything then repasting everything (except CPU seeming as you have already done that). As Doolittle says above, do the Southbridge, but also do anything else that had a heatsink, to make sure all parts are good.

Do everything circled in red in the picture below, that you have on your motherboard, to see what happens.

Also, would be worth checking the PSU under relative load. Look for the rail voltages I'm the BIOS. Specifically, +12v, +5v and +3v. Are they close to what they should be, or not?

 

[Apcoolboy]

Great, that narrows it down - and also had a similar situation with an old gigabyte board with an X2, the southbridge overheated so I repasted but now it only will boot from USB or SD card using a floppy interface card reader, none of the sata ports will recognize any drives. Linux or nothing on that one now lol - it's worth a shot to maybe save the board, go for it!

So as I mentioned that block written "GIGABYTE" on it getting heating up. Also overnight cooled pc boots normal and runs for almost 2 hrs. So what exactly my problem is? Also what exactly I have to repaste? Sorry, I haven't repaired any part of mobo so very new here.

But after I research little bit on my problem and as you mentioned about south bridge, I am able to understand that smothering is heating up under that block due to old thermal pads/paste is dried out. And simple solution is that I need to remove old thermal pad/paste with new one (which I can do myself). But I'm concern about if I unscrew those things get me more problems. Any detail forum or something where I can have it as reference?

Thanks in advance

 

[Apcoolboy]

I think it would be worth taking the thermal paste off everything then repasting everything (except CPU seeming as you have already done that). As Doolittle says above, do the Southbridge, but also do anything else that had a heatsink, to make sure all parts are good.

Do everything circled in red in the picture below, that you have on your motherboard, to see what happens.

Also, would be worth checking the PSU under relative load. Look for the rail voltages I'm the BIOS. Specifically, +12v, +5v and +3v. Are they close to what they should be, or not?

Thanks for response,

I am getting clear picture what might be problem. As you and doolittle said, I am going to replace that thermal paste under south bridge and other available blocks as your pictures says. Just one question, is there would be simple flat surface as cpu has? And thermal paste would be applicable there? Or need something other like thermal pads (saw in one youtube video).

TIA

 

[ConanLock]

Thermal paste will work fine, like on the CPU. In my experience, the paste that is put on there in the factory is really sloppy and oozing out of the sides anyway. You'd struggle to do any worse than that 😂

 

[Apcoolboy]

Thanks all, Northbridge was heating real quickly. And it was behind my sudden shutdown. Never changed thermal paste for North & South bridges before. As you guys suggested, I change thermal paste for both bridges and my GPU as well. Now PC runs smooth.

Also when I inspect temperatures of mobo sensors in diffrent programs like speedfan, AIDA64 and HWMonitor, It shows Northbridge temp goes around 55 C. Is it normal? just wondering.

Thanks all for the help. I really appreciated.

 

[ConanLock]

Yep, that is a good temperature. Same as with CPU and GPU, the max is about 80°C. It's great that it's working again, I'm happy to have helped.