New Build Problems - Asus P6T

[mattg1981]

First I totally built computer, hit the power switch and nothing at all .. tore it down <stupid me>

Built it on a cardboard box with just CPU, Heatsink (Zalmon 9700), 1 stick of ram in A1 (first orange slot), and video card (4870 1gb). Power supply is a ZALMAN ZM750-HP 750W. Since it didnt boot the first time, stupid me tried different configurations of the power connections to the board (8 pin 12v and 24 pin main connection). Both of those connections come in two parts on the power supply so i plugged in the 1x20 main connector and the 4x12v into the 8x12v (4 of the 8 have a black cap over them from the factory on the board).

Well it powered on (blue led on power supply turned on, CPU blue led fan on and fan churning). I look at screen and stupid me "Video card power not plugged in". Whooops, so i plug it in, reboot (all this time using onboard power button) and look at screen "Dummy, you didnt plug in a keyboard". Whoops, plug that in and reboot and looking back to my surprise, I got to the BIOS.

I looked through the BIOS and it detected the CPU correctly, the 1gb stick of ram was also detected. I made no changes to the BIOS. I got up to get a drink and all of a suddon on my way back, it lost power ... like a brownout .. it almost lost all power, surged back up, almost lost power, semi surged up, and then poof, it was off.

That was all the success i've had with it. I have since connected all 24 of the main power and 8pin 12v of the CPU power but now I get no posting at all. I still get power when i turn it on, the GPU has 3 green lights that turn on for about 5 seconds and then those turn off, 3 red lights come on and fan speed to 100 percent. I also get no PS/2 keyboard power anymore. I removed the onboard battery overnight and switched the clear jumper like manual says.

I have no onboard speaker so I cant hear any beeping if there is any


So Basically ...
It could be the PSU (brownout like affect makes me suspect that, but also consider i didnt give the board full power)
It could be the GPU (3 red lights D1601,2,3 on ... meanings listed in this thread.
It could be the Motherboard

I am also reading that people are having problems with aftermarket CPU coolers on i7 boards, and them not sitting flush, so in the very back of my mind there is a chance i overheated the CPU, but i have no signs .. no smoking, no smell, nothing like that occured.

I have no tools to test the voltage coming out of each rail to see if its a bad PSU. What do you guys suggest I do, and if its RMA, which one do I send back first?

 

[techmanc]

Do you have a suspected parts you can swap out with a known working unit? e.g. psu gpu

 

[mattg1981]

unfortunatly none that will power this card .... I do however, have an old x800xt (pcie 1.0) card which I am going to try next and if it passes that test, then it would be between the video card and the PSU not pumping out its advertised juice. IDK if I could use the old PSU though cause it probly doesnt have the 8x12v CPU power pins.

So really all I can do is swap out the video card but that would still leave two unknowns if that were to work. When I get home I will try that and hopefully have more information

 

[mattg1981]

I was able to test the power supply and GPU and both work. I hooked power supply up to old computer using the 1x24 and 4x12v CPU power. So that narrows it down a bit.

That leaves:
A) the other 4x12v CPU connector on PSU faulty (unlikely)
B) The motherboard
C) Either the CPU or the RAM ... I luckily have 6 sticks of RAM I can test, so the chances those are all bad is slim to none (and the fact that it was detected in BIOS the first time).

Being that the CPU was also detected by the BIOS that first time it ran, I think that wouldnt be the problem either (although its possible that i could have overheated it ... but just in the BIOS, do you think it would ruin the chip? I dont think so).

So by elimination, I would say its the motherboard (now why it worked for about 45 seconds and then died is beyond me). Would you guys agree with this statement?

 

[Tweakin]

Well, I have had a great deal of issues with the seating of heatsinks on my previous boards...but what happens is the system will boot for 30-45 seconds until the chip hits thermal shutdown...then nothing.

If you let it cool off, it works fine again for the same amount of time. Point is I don't think this is what you have, sounds like your board is fubar.

 

[mattg1981]

thanks tweak, was wondering what the symptoms of an overheated CPU were.

Went ahead and RMA'd i'll let you know how the build goes once i get new one back