PC Tech needs help!!!!

[tootallr6]

A customer brought me a new custom build and said the video was not working. I connected it to a workstation and the system was doing the power on/off cycle on about a 5 sec. interval. I removed the GPU, reset the CMOS, removed MOBO and checked the standoffs, reseated the CPU/heatsink/paste, verified wiring was correct, unplugged DVD drive and hard drive, removed and reseated the RAM and tried both sticks by themselves. PSU tested OK. Also let the system just run the cycle for about 5 minutes. All to no avail. What am I overlooking?

System Specs:
Mobo ASRock B75M-DGS
CPU i5 3470 3.2ghz
RAM 2x4GB Patriot 1600 pvi38g160c9k
PSU Corsair CX500
GPU EVGA GTX 660 (has been removed thru entire trouble shooting process)

On a side note the RAM is not listed on the MOBO supported list. I don't have any replacement RAM that is listed either. I'm going to feel really stupid if this is the problem.

 

[HiTechObsessed]

Well, are you getting POST? If RAM is the problem, it would (well, should) give you the beeps that RAM is bad. If no beeps at all, make sure he has MoBo speaker, or it might just be a bad MoBo.

Also, how did you test the PSU? Simply verifying power output isn't always sufficient, if the PSU isn't completely dead yet it might only fail on higher loads. You might try grabbing a separate, known-to-work PSU to test it out just to be sure.

 

[tootallr6]

Tested PSU with a multimeter while running 2 fans, all voltages were well within tolerances. When connected to a monitor it says no signal and goes to sleep. No beep codes are given.

Not sure how this factors in, but I accidentally left the secondary 4 pin power connection on the MOBO off and the system remained powered on, was not connected to a workstation at the time. Should I try it on a station without that 4 pin connected?

 

[HiTechObsessed]

Tested PSU with a multimeter while running 2 fans, all voltages were well within tolerances. When connected to a monitor it says no signal and goes to sleep. No beep codes are given.

Not sure how this factors in, but I accidentally left the secondary 4 pin power connection on the MOBO off and the system remained powered on, was not connected to a workstation at the time. Should I try it on a station without that 4 pin connected?

By 4 pin do you mean the CPU power? And I still recommend trying a separate PSU, 2 fans aren't gonna pull the power needed, but it's not very probable.

Also, does the MoBo have a built in speaker or a speaker plugged in? If it's not POSTing, it may be a bad MoBo

 

[tootallr6]

Yes the CPU 4 pin power connection. I plugged in a speaker to the MOBO output port on the back of the system. I knew the 2 fans weren't pulling a full load, but with everything being brand new one would assume that the PSU is OK since everything was above tolerances. I'll try a different PSU and get back to you.

 

[HiTechObsessed]

Sorry, I meant a MoBo speaker, that plugs directly into the MoBo, not an actual speaker. This will give you the POST beep(s) to tell you what's wrong if it's something the MoBo can figure out. Otherwise, I'm starting to suspect a faulty MoBo.

And like I said, PSU's can be bad but still allow power draw. It's not a very big possibility, but it is, and since this is a computer we're dealing with, I try to think of everything! Because it's almost never what you expect right off the bat lol

 

[tootallr6]

Sorry, I meant a MoBo speaker, that plugs directly into the MoBo, not an actual speaker. This will give you the POST beep(s) to tell you what's wrong if it's something the MoBo can figure out. Otherwise, I'm starting to suspect a faulty MoBo.

And like I said, PSU's can be bad but still allow power draw. It's not a very big possibility, but it is, and since this is a computer we're dealing with, I try to think of everything! Because it's almost never what you expect right off the bat lol

I tested with a known good PSU same results. That narrows it down to the MOBO or CPU. I'm betting its the MOBO. It will be after Christmas before I can test either one. I'll let you know what I find out. Thanks for all your help and Merry Christmas.

 

[tootallr6]

Its the MOBO. I tried a speaker, still no beep codes. Replaced the MOBO with a known good part and everything is working. Thanks for all your help.

 

[HiTechObsessed]

Its the MOBO. I tried a speaker, still no beep codes. Replaced the MOBO with a known good part and everything is working. Thanks for all your help.

No problem, glad to help!