(Random shut offs) BIOS reading conflicting with DMM on +12v rail (11.3/12.08)

darkdavid08

Junior Member
Sep 14, 2015
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Pc has been event 41 shutting off for a while, replaced my GPU and PSU because of it, here are my current specs:

I7 920

Asus rampage ii gene (cg5290)

CM g750m (3 months old)

Msi 280x 3g (6 months old, bought used)

3x4gb patriot g series 1600

Seagate 1tb 7200 sata

CM hyper 212 evo

Basically I noticed a low +12v rail in my BIOS hardware monitor (jumping between 11.1-11.4), especially after a shut off. However on my DMM, I probed the +12v on the molex,pcie,and every other power cord that has that rail including the motherboard ones and they all read 12.08v stable at the same time the BIOS was showing the 11.1-11.4v readings.

Does this mean my 6 year old motherboard is dying? Or could it be the 3 month old PSU calling it quits? Alternatively the used GPU I have could also be a culprit.

Looking forward to hearing your responses

Ps: memtest, sfc /scannow, chkdsk (all passed); temperatures and GPU/CPU usage % all normal.
 
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VirtualLarry

No Lifer
Aug 25, 2001
56,186
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Basically I noticed a low +12v rail in my BIOS hardware monitor (jumping between 11.1-11.4), especially after a shut off. However on my DMM, I probed the +12v on the molex,pcie,and every other power cord that has that rail including the motherboard ones and they all read 12.08v stable at the same time the BIOS was showing the 11.1-11.4v readings.

Does this mean my 6 year old motherboard is dying? Or could it be the 3 month old PSU calling it quits? Alternatively the used GPU I have could also be a culprit.

Not really. Software voltage readings should never really be trusted, unless calibrated with a DVM.

If your DVM is reading ok, then low +12V is probably not the problem.

Is it a multi-rail PSU? Does it have enough PCI-E power connectors for your GPU? Or are you using a Molex-to-PCI-E adapter?
 

darkdavid08

Junior Member
Sep 14, 2015
5
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Not really. Software voltage readings should never really be trusted, unless calibrated with a DVM.

If your DVM is reading ok, then low +12V is probably not the problem.

Is it a multi-rail PSU? Does it have enough PCI-E power connectors for your GPU? Or are you using a Molex-to-PCI-E adapter?

single rail, only reason I was checking was because I started getting event 41 shut offs randomly, and that prompted me to check the voltages in the BIOS, where they were under spec (even had my pc shut off IN THE BIOS). Since the +12v was the only reading showing out of spec, I decided to check it with a multimeter. It came out to 12.08. I was wondering if the BIOS missreading voltage Is this indicative of a dying motherboard or potentially something else?
 

darkdavid08

Junior Member
Sep 14, 2015
5
0
0
Do you have a UPS (battery backup)?
No I do not, only a surge protector, but an expensive one. I initially thought it was the outlet in my room, or a faulty surge protector, seeing as how the shut offs seem power related (pc just looses power than powers back on after a few seconds). First things I checked before troubleshooting. I checked both extensively with a DMM, voltages are stable and grounding looks good on both. So its probably not the wall outlet, or power strip I'm using.
 
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VirtualLarry

No Lifer
Aug 25, 2001
56,186
9,961
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The reason I asked, is, I ran into an incompatibility between my Delta-made Antec Earthwatts 500W PSU (a great PSU otherwise) and my CyberPower 550VA / 330W UPS.

When the UPS went to switch to battery, even for a split-second, it would trigger a PSU shutdown, and the PC would reboot.

I have since replaced them with more modern PSUs (EVGA 500W) that don't reboot.

The problem was the PFC in the PSUs.
 

Burpo

Diamond Member
Sep 10, 2013
4,223
473
126
Does this mean my 6 year old motherboard is dying? Or could it be the 3 month old PSU calling it quits? Alternatively the used GPU I have could also be a culprit.

Looking forward to hearing your responses

It's probably time for a good cleaning of fans & maybe some new compound between CPU & heat sink. I'd check fan speed & temp of GPU. It may need new heat sink compound as well. I had similar problem on T3500 Dell with an older Nvidia card. A good cleaning & new heat sink compound for the GPU cured it.
 
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