Intermittent non boot on new build, motherboard/cpu problem?

Dejafu

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Jan 27, 2015
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4,510
Hey there, first post but I've been searching through threads all day.

I'm in the process of upgrading my PC, and for the most part it is not booting. All the fans starting working and spinning, but no video output, no beeps. The weird part is that occasionally it does and I can go to bios and it seems to be working fine. Then, when I turn it off again, back to the no video, no beeps, just fans.

I've gone through the troubleshooting thread. I've checked my cpu pins. I've tried this with and without the graphics card (same thing, sometimes it works, most of the time it doesn't), with one stick of ram and two sticks of ram, literally everything I can think of to try and isolate this issue but no avail.

I know that the PSU works as it is the same one from my previous Mobo. Since the bios works, is this issue likely to be with the CPU? Or since most of the time the boot doesn't make it to bios, could it be the motherboard?

Specs:
Cpu: i7 2600k
Mobo: Asus p8z68-v lx
RAM: Kingston HyperX DDR3-1600 CL10 240-Pin DIMM
CPU cooler: stock
SSD: Intel 530 120gb
Video Card: GTX 560
PSU: 650 watt Master
Case: an old cooler master
 
Make sure all cables, DIMM's and video card are inserted properly.

The PSU may be just starting to fail. Recommend trying another known working PSU (at hand or borrow one) as a test.

If problems continue with the other PSU installed, then suspect the motherboard may be faulty.
 

Dejafu

Reputable
Jan 27, 2015
5
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4,510
The SSD and RAM are brand new, straight out of the box.

The PSU is old, but working just fine with my other motherboard and CPU, so I'm 99% it can be ruled out. Same deal for the graphics card.

The i7 2600k I'm installing and the motherboard are second hand, and I'm thinking the issue might be with one of them.

For the majority of times when I turn it on, there is no video output and no beeps. When it does work, there is one beep and then bios will boot. Occasionally after this happens, everything will run normally for a while, but then the screen with flash through solid colours. Other times I have turned the computer off after it has gone to bios, and when I have tried to turn it back on it has encountered the no video, no beeps, just fans, issue.
 
try a new cmos battery...before you do make sure the mb has the newest bios file to rule out a bios issue.
check the power good pin on the mb. try the system post with one case fan removed..may have a bad fan or to many devices in the usb port and your setting off asus anti surge.
 

Dejafu

Reputable
Jan 27, 2015
5
0
4,510
Tried it with only CPU+fan, PSU. Did the no RAM beep.

Added 4gb of RAM, booted, went to bios. So I turned everything off and added another stick of RAM. Didn't boot.

So I switched the RAM over to test that. Booted.

Added the other stick and it booted with 8gb of RAM. Went to bios but the mouse wasn't working. Unplugged the mouse and then it crashed to a coloured screen (grey, colour seems to be random).

Hasn't booted since with any combination I've tried. Thinking it's the mobo since a dead cpu seems unlikely. I'll but a new one tomorrow and see if that is the case.