PC shuts down abruptly in the first few minutes of working, help pls!!!!

[Koda]

I've been repairing PC's for a few years and haven't come across this problem so far and I'm out of options. The PC would just shut down randomly and abruptly sometimes after a few seconds and sometimes after a few minutes of working and sometimes it won't power up at all just a fans spinning a little during the first second. Normal troubleshooting procedure, checked memory, gpu, HDD, battery and dvd writer in another pc and all is good, checked for bad caps and all seem ok. replaced the PSU with a known good one. Last thing to check was the cpu temps. First time I checked them BIOS showed me temps in the 30C range, pretty good but problem still persists. So I think what the heck and I reseat the CPU and replace thermal compound and behold, the PC worked like a charm. Gave back the PC to the customer and after a few days I get a call back from the customer complaining on the same symptoms. So I take back the PC and again same thing. I reseated the CPU and the heatsink again and I noticed that the motherboard was bent a little from the force of the heatsink was putting on the motherboard so I decided to run the damn thing with the heatsink seated but not secured and woila, PC boots and runs properly. I slowly and with great care secured the heatsink once again. Started stress testing the cpu with Prime 95. The thing ran with temps in the 30-40C range for about 10 hours. All is well I think... Gave the PC back yesterday and ONCE AGAIN, customer calls and here I am with this damn thing sitting next to me. Same symptoms and in desperate need of your help. I have no ESR meter to check the caps. No spare motherboard or cpu to test these things and no new ideas. PC specs are as follows.

MB: Asus M2N
CPU: Athlon 3800+ 64 x2
Ram: Kingston 2GB DDR2 800
GPU: Inno3D 7300GT
HDD: Seagate (don't know the model) 320GB

I'm at the end of my nerves guys pls help.

[Uranium-235]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

go over there!

do a memtest86+

[c_hegge]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

nVidia chipset - There's your problem

[Agent24]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

Yeah it does sound like some physical problem if stress on the board with\without CPU cooler attached properly makes a difference.

Could be bad solder balls on the chipset, could be something else.

[Evil Lurker]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

Flakey board, classic Nvidia chipset issues.

I would recommend replacing it with something else before investing any more time and trouble into it.

[Koda]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

Well no longer my problem, the customer got angry and took his PC back this morning. I refunded him and he went on to another tech. and hour later called me to rub it in my face that the PC has been repaired and by the words of the other tech the CPU wasn't placed correctly in the socket His words : "the pins of the cpu weren't completely inserted in the socket" (don't know if that's even possible) . Knowing that I placed the CPU correctly because I always triple check when I'm messing with the CPU I was a bit offended but I also know that this new repair won't last very long and he and his new tech will be in a world of trouble with this demonic PC So at least I get a little satisfaction. btw the temps of the motherboard were ok for an nVidia chipset. checked that too. The motherboard could have needed a reflow but not my problem anymore. This guy is my first ever unsatisfied customer but what the hell.

[Agent24]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

I don't think overheating is the problem with these chipsets (or any), I believe it's more likely bad solder balls between BGA package and PCB or internally to the chip package itself.

[c_hegge]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

Well, ASUS boards often end in unhappy customers for us too.

[Koda]

Re: PC shuts down abruptly in the first few minutes of working, help pls!!!!

go over there!

do a memtest86+

Did a memtest the first two times just to be sure. Nothing wrong, the PC would still show the same symptoms with 3 other known good sticks of memory.

Yes most probably its the chipset BGA needing reflow I'm the only one in my town that's doing BGA reflow and hell probably end up replacing the motherboard and paying a hell of a lot more then if he would just be patient and waited a day or two more.
I didn't think of the BGA chipset cause the motherboard would work fine for prolonged periods of time after I did the repair. But probably reflowing would have been my next step. Oh well what the heck.