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12V rail shows 16V, CPU temp -1C

Last response: in CPUs
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January 12, 2011 2:26:26 AM

problem started when my pc hanged, no BSoD then restarted over and over. after 3 restarts, pc stopped before os loads then followed by "detecting array..." then i let my pc rest for a few days, my pc became ok but when i checked the hardware monitor it was not ok.

hardware monitor shows 16V on 12V rail, even the other rails are over their voltages.

then i tried to reset the BIOS, still the same but CPU temp dropped to -1C.

may i ask what is wrong? im not so good with hardware problems.

i forgot to mention im only using my on board video card.
a b à CPUs
January 12, 2011 8:12:04 AM

Have you tried any other software to show your voltages and temps?

For the longest time Everest Ultimate said I was running 1.5v on my +3.3v, and it was only when I changed my CPU from a 720BE to 1090T that it showed correctly.

Ebuyer have a device that lets you test your PSU's output, which for £10 isn't a bad product to have handy. Let me find the link.. http://www.ebuyer.com/product/202783
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a c 172 à CPUs
January 12, 2011 7:41:28 PM

Use a DMM to measure the PSU voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.
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January 13, 2011 5:02:15 AM

well this is what my hardware monitor says:



@dadiggle

processor: AMD Athlon LE-1620 2.4GHz
mboard: mcp6p-m2 biostar
memory: 512mb DDR2 forgot the brand show 382mb on dxdiag
vcard: nvidia geforce 6150se integrated ramdac

by the way i dont know what my psu is but it says 500W.

@acer0169

nope, i only use the one in BIOS and the hardware monitor i installed

@jsc

sorry i really dont have any knowledge about electronics and stuff like that.
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a b à CPUs
January 13, 2011 6:29:41 AM

The temperature is obviously wrong. I doubt the CPU would survive 3 V. The OVP on the PSU should be shutting it down if 12 V reading is correct. I would probably suspect your motherboard.

When it restarted, there may have been a BSOD, but it would have restarted almost immediately. Is it still re-starting?
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January 14, 2011 11:34:35 PM

may i ask if room temperature greatly affects the system unit? because these past few weeks, our room temperature was between 23 - 25C, it was always cold and raining.

is my Hardware Monitor reliable in checking voltages and temperature?

@Preferlinux

may i ask what OVP means?

seems BSoD is disabled in my BIOS that's why i didn't encountered any.

restarting stopped when i didn't use it for 2 days. but when i turned it on, everything was over their voltages so i let it rest again. the next day, i reset the BIOS and after that, the -1C happened.

it never restarted again, even with the -1C and the whacked voltages. but i don't use it too much now cause i'm afraid i might damage it more.

@Dadiggle

nope never tried speedfan cause i never use my pc anymore for more than 5 minutes. i'm scared to worsen the damage.
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a b à CPUs
January 14, 2011 11:43:34 PM

OVP = Over Voltage Protection
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a c 191 à CPUs
January 15, 2011 1:34:04 AM

Check the voltages in BIOS, software tends to guess at what voltage monitoring chip you have, sometimes it guesses wrong, BIOS is much more accurate, but the only way to be certain is with a multimeter.

As others have said, if you really had 16V coming off your 12V rail, you would have fried every VRM in your system by now and let the magic smoke out of many other parts, so i highly doubt that hardware monitor is reading it properly.
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January 20, 2011 5:49:54 AM

well our multimeter was already broken so i can't test it. and even if i have a multimeter, i don't know how to use it. :p 

may i ask if there is a reliable software that reads voltages and cpu temp? seems my BIOS reading is the same as the one in my hardware monitor.
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