12v running too high?

jt001

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Dec 31, 2006
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So I've killed 2 boards in the past few months, and my system has been generally unstable lately. I hooked up a voltmeter and my 12v is running at 12.45v, that seems a little too high to me. Is this likely the cause of my problems?
 

Zorg

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That is within specification. I don't know if it is to hot for your mobo though.

developer\specs\PSU_DG_rev_1_1.pdf Page 22
 

JohnnyMash

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I would also check on your power supply. If it wont supply enough wattage, then taxing it to its higher limits can cause the voltage to increase as its tries its utmost to provide power. As Zorg said, not out of spec, but it may not just be your +12V that is over and above the norm. Swap it out if you have a spare, or get a new 600+ watt'er, for when you get your new quad core rig!!!
 

jt001

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It's definitely not near the limit, I'm probably not even pulling half of what it's rated.

Almost half a volt over seems a bit high for something in a PC though. I'll probably look into a new PSU as this one is showing it's age anyway.
 

cyberjock

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Without going into alot of detail, a voltage regulator will output a curved voltage out. With no feedback at no load you might get 12V, at 10% load it might be 11.9V, at 100% it could be 9V. Obviously this is bad as 9V won't keep your computer on. The solution is feedback to the regulator. Unfortunately it's not a cut and dry set it and forget it. They have a range they have to stay in so they have to set the feedback. You are running somewhat high, but are still within spec. It could be that your PSU is actually going out of spec at certain loads. It could also be that the 12.45v is more of an indicator of something more serious wrong with your PSU, for instance the filter circuit might not be cleaning up the AC and you have a voltage ripple that's ruining your MBs. I'd say that although 12.45v is within spec, I'd be skeptical of it. Replace it with a spare and see what happens.

Also, is your voltmeter calibrated? Does it actually give an accurate voltage for the range you are using? If you are on AUTO you should be concerned with the exact range that AUTO is choosing for you.
 

altazi

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That's only 3.75% high, which shouldn't be a problem in itself.

In addition to the good reply from Cyberjock, it is possible that your PSU is regulating based on another supply, e.g., +5V. If you have too high of a load on the +5V supply, the PSU will have to compensate accordingly. This could cause the other output voltages to rise.

What are your other supply voltages? Any of them look "out-of-whack"?

Regards,

Altazi