[SOLVED] EATX 12V Failure?

[superbrett2000]

My motherboard fails to even power on when I have both the 24-pin and 8-pin power supply cables plugged in. If I remove the 8-pin cable, then the motherboard is responsive (a little fan on it will start spinning) but I get a red CPU failure light on the motherboard. When I have the 8-pin cable plugged in, the motherboard won't even get to the point where it shows this light. The computer never reaches the post state, so nothing appears on screen.

Any ideas on what's going on, and a possible fix or other thing to try? It's most likely that the motherboard has failed, so this is my last ditch effort to salvage it. I've also never had a motherboard go out on me either, so this is new territory... The motherboard does not have any physical damage, burn marks, visually broken solders, capacitors, etc.

What key components do I have?

• Motherboard: Asus TUF Sabertooth X79, LGA 2011
• CPU: Core i7 3930k
• PSU: 750 watt

How do I know it's the motherboard?

• I've tried two different CPUs with the same result described above.
• CPU pins are in good shape, and not bent.
• Two different power supplies were also tested, both 750 watts.
• The RAM was installed on another computer and didn't present an issue there.
• Two different graphics cards were also checked.

 

[CountMike]

My motherboard fails to even power on when I have both the 24-pin and 8-pin power supply cables plugged in. If I remove the 8-pin cable, then the motherboard is responsive (a little fan on it will start spinning) but I get a red CPU failure light on the motherboard. When I have the 8-pin cable plugged in, the motherboard won't even get to the point where it shows this light. The computer never reaches the post state, so nothing appears on screen.

Any ideas on what's going on, and a possible fix or other thing to try? It's most likely that the motherboard has failed, so this is my last ditch effort to salvage it. I've also never had a motherboard go out on me either, so this is new territory... The motherboard does not have any physical damage, burn marks, visually broken solders, capacitors, etc.

What key components do I have?

• Motherboard: Asus TUF Sabertooth X79, LGA 2011
• CPU: Core i7 3930k
• PSU: 750 watt

How do I know it's the motherboard?

• I've tried two different CPUs with the same result described above.
• CPU pins are in good shape, and not bent.
• Two different power supplies were also tested, both 750 watts.
• The RAM was installed on another computer and didn't present an issue there.
• Two different graphics cards were also checked.

That symptom is usually an indication of VRM failure.