Windows 7 - My 12V rail is only giving 8.01V

Hey guys,

According to CPUID Hardware monitor, my +12V is only giving out 8.01 V. What could be causing this? and how can I fix it? The 5V is a little low at 4.71 V but thats pretty close.

Any ideas?

Thanks in advance.

Is anything not working correctly? could be cpuid, your PSU, etc.

Everything seems to be fine, no errors or anything. Maybe its just CPUID.

The only way to truely test this is the old fashion way....

get out that hunk of junk called the multi meter... and check it that way from your PowerSupply

if your getting the same voltage as the software is reading then your powersupply is having issues.

You didn't do that (absolutely insane) 7 Volt fan mod trick in your machine did you? The one that's so popular on these hot dog modding forums?

I'm not trying to sound like a jerk here, I ask because that mod will often do that to your 12V rail when the PSU inevitably breaks down. (And that method of fan control is a seriously stupid way to achieve what a $7 Zalman fan controller will accomplish without totally risking your hardware.)

When you do check with a multi meter, make sure that you check the voltages when they are loaded. That means leave everything connected. Check the voltages at the motherboard connector and one of the available drive power Molex connectors (That one doesn't have to be connected to anything.)

If you have the same voltages as Hardware Monitor is showing you, shut down the PC and disconnect all power supply connections, and remeasure with no load on the PSU. If your voltages come back to what they should be, there are a few possibilities:

1. You're overtaxing your PSU and the voltages are drooping under the load. You need a bigger PSU.
2. Your PSU is going bad. Need a new one.
3. There is a problem in the power control circuitry in the motherboard, or there is a peripheral card or component that is failing/has failed.
4. If you did the fan mod, the PSU might be damaged completely. See #2 and count your blessings that the mod didn't put 12V on your 5V rails.

Here are a few articles on how to go about checking your power supply with a multi meter.
Power-supply troubleshooting with a multimeter

Power Supplies 101: A comprehensive guide Motherboards.org

Testing Your PSU Rails - EXTREME Overclocking Forums

Hey bud,
No I dont even know what fan mod you are talking about. Everything in my computer is stock, and not over-clocked. I can check it with the meter to see if its just the software, I hope so :-).

Its a 700W psu so It shouldnt be over stressed because im only running one video card, the cpu, and all the normal stuff, hd,dvd,

I will check it later tonight and see if its working right.

A decent quality 700W or a cheap one?

P.S. pretty sure that the computer wouldn't even boot if the 12V rail was only outputting ~8V.

Excellent. That's what I was hoping to hear.
I was thinking about this yesterday, and I forgot to mention the possibility that it might just be a flaky sensor in my last post.

Depending on the motherboard, different programs will read the voltages and stuff differently. You might want to try out Speedfan or Everest (the free edition will work, I think.), and compare that with what the BIOS says the voltages are.

The 12V reading you're getting might be the -12V rail, and that can be all over the place. Hardware Monitor might just be reading the wrong sensor, not the wrong voltage. The fastest way to check would be to take measurements with your meter on an unconnected drive power connector. If you see 12V and 5V there, you should be okay.

Hope it works out.