ASUS Sabertooth Z77 CPU_LED

Jinzhou

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Dec 17, 2008
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Rig:

i7-3770k (LGA1155)
ASUS Sabertooth Z77
4x 8GB Corsair Dominator Plat RAM (Lat: 10-11-10-30)
NVIDIA Quadro 4000
2x 500GB Samsung SSD's
Corsair 850W PSU
Coolmaster Case (can't see model, but it has USB/3.0/1394 Connectors)


This is my co-workers rig.

1. There was apparently a virus on our server (my workstation is unaffected) and now the co-workers comp crapped out (don't know if it's related).

2. Power on, lights come on for about 5 seconds and then power off-- but during this time the CPU fans attached to the Z77 cover were still spinning, so there was still power going to it but nothing else.

2.5. The CPU_LED light was the only steady light.

3. Reset the BIOS/CMOS (moved the jumper pin / removed/replaced the Mobo Battery).

4. Removed all components except 1 stick of memory Same thing.

5. Eventually I found that a USB Header was (seemingly) drawing too much power and upon removing an NZXT 6-in-1 reader everything seemed fine.

6. After this is booted up fine, but within the day it was freezing.

7. Deleted the bad partition though Windows Installer, installed fresh copy of Win7 Ultimate on 2nd SSD-- works fine for the whole day.

8. I come in today to find that the computer turns on, won't POST and the CPU_LED is staying on constantly, as well as power to the fans, etc. (CMOS/BIOS Reset doesn't do anything).

9. I have now removed every component, including the CPU and have found that no pins are bent on the CPU Socket, none of the pads on the CPU look off, nothing looks/smells burnt; none of the transistors/capacitors on the board look burnt.

As of right now I'm at a loss, so any help would be greatly appreciated.
 
Solution
sounds like either the motherboard is going flakey, the on-off circuit to be more precise and it happens a lot on motherboards, or less likey, the power supply. PSU is easy to test, pull one from a working system. If not, it's the board.

And FYI, the virus would be unrelated to any hardware problems like a board not booting.
sounds like either the motherboard is going flakey, the on-off circuit to be more precise and it happens a lot on motherboards, or less likey, the power supply. PSU is easy to test, pull one from a working system. If not, it's the board.

And FYI, the virus would be unrelated to any hardware problems like a board not booting.
 
Solution

Jinzhou

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Dec 17, 2008
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Thanks for the reply; yeah I had just mentioned the virus simply because the timing seemed way too convenient and I thought maybe a file was grabbed from the server that caused an issue.

I'm bringing the rig home with me tonight to run more tests, but the PSU was working fine yesterday-- would it work intermittently or would it just be black-and-white?