Help needed: Got a problem to diagnose, i'm clueless.

C

Ctek

Weaksauce
Joined
Jul 26, 2011
Messages
115
Hi,

I built a new PC 2 months ago, and while I don't post often here, I'm no newbie. The setup is as follows :

Core i3 3.1ghz
Gigabyte B75M-D2H mobo
8GB Kingston DDR3 Ram (2x4gb)
Hitachi 1TB HDD
Coolermaster 460w PSU
DVDRW
USB 2.0 PCI card (to add an USB header to the system).

System has been having problems since I gave it to the customer. Problems were freezes in windows, instant restarts without BSOD, computer locks-up before or during loading windows.

I took it back for repair last month, and I diagnosed no problems at all here. I update her mobo BIOS (a new version came out in the meantime) and I give her back and install everything at her place correctly, including properly installing drivers for her printer and whatnot.

Last week, still having the same issues but now she can't boot. Go to her place, diagnose the computer and I find out that the hard drive was knocking hard. Bad HDD so I install a new Seagate 1TB in, completely reinstall anything from scratch and once I was done, after some windows update s and reboots, the motherboard makes continuous beep sounds while booting. I makes more than 25 of it then shuts down. After 5-6 tries, it finally boots and then proceeds to enter windows flawlessly. After a couple of other reboots, it makes the same thing again. I take the computer back at home with a no so happy customer.

So I order a new motherboard, same one, and a new PSU. I install them and guess what, same problem. I remove the USB add-on card and same problem occurs.

So bottom line, I am currently debating myself if the CPU is the problem because it seems that way AFAIK.

Can a CPU be defective while only behaving improperly intermitantly?. Do you have any suggestions or comments about my issue?
 
What was the old PSU and the new PSU? Did you try a different set of RAM?
 
Initial PSU : Coolermaster Elite 460w.

New PSU Antec Basiq 350w.

I'm trying new ram this afternoon.
 
Ctek said:
8GB Kingston DDR3 Ram (2x4gb)
. . .

So I order a new motherboard, same one, and a new PSU. I install them and guess what, same problem. I remove the USB add-on card and same problem occurs.
Click to expand...

I used to think that CPUs were either 100% OK or 100% dead, but somebody proved that surge damage could let one still work but not at full speed. Can you slow down the CPU bus to see if that makes a difference? If it does, the problem could still be something else, and I'd look at another common denominator, like the memory, especially anything made from no-name chips (as Kingston usually is) or was factory overclocked (common with heatsinked memory). I'd test with modules made from name brand chips (Samsung, Micron, Hynix, Elpida, etc.) and no heatsinks.
 
Strangely, after removing the board from the case, and running the whole setup on a cardboard box, the problems seems to have gone away. I can't see the issue in the case (if something was touching the backside of the mobo).

Now everything is back in and I can't make it fail again... what a strange problem.

Can a grounding issue be the source of all my problems?
 
Ctek said:
Strangely, after removing the board from the case, and running the whole setup on a cardboard box, the problems seems to have gone away. I can't see the issue in the case (if something was touching the backside of the mobo).

Now everything is back in and I can't make it fail again... what a strange problem.

Can a grounding issue be the source of all my problems?
Click to expand...
It's common, even though motherboards are supposed to be designed so the mounting holes have no signal or voltage traces running close to them. Inspect each hole on both sides, and add fiber insulator washers as needed. Also check how close the corners of the mobo get to the case because mobos and cases can flex enough to let them touch, so any corner more than 2" from a support post should get a rubber stick-on foot placed under it (stick it to the case). Some mobos have holes in the corners that aren't made for support posts, and you can put nylon standoffs in them (trim to length if needed so the mobo won't be bent).
 
You must log in or register to reply here.
Back
Top