Possible Power supply issue

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islhopr

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I have a Evga 1600 wat Power supply, that will drop the 12v rail down to 10.8 volts, at times. The voltage keeps changing ? up and down ?
 
islhopr said:
I have a Evga 1600 wat Power supply, that will drop the 12v rail down to 10.8 volts, at times. The voltage keeps changing ? up and down ?
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That sounds like it may be current limiting. What are your operating conditions? Specifically, what is the load?
 
Under what load conditions? Obviously if you are using the PSU under normal conditions it should be regulating. The 12 VDC out should maintain +/- 5% so 11.4 VDC to 12.6 VDC and it should be stable. The EVGA Super Nova 1600 should have come with a 10 year warranty. Additionally the 1600 Watt means little to nothing. The 12 volt rail should be able to deliver 133.3 amps total at the expense of the 3.3 and 5.0 volt rails. The PSU should also have a self test at power up.

So again, what is the load on the PSU?

Ron
 
Well that hard to explain? the AMD 3900x does takes a lot of power, then I have the NVidia 1080ti, One water pump, 20 rgb fans, takes up the most power ? Running a crosshair Viii motherboard
 
In a standard PC the supply should regulate. While you have some load there it is not enough to cause the supply to behave the way it is. My best guess is a faulty supply. Ten year warranty so I would look to send it back wherever you got it from.

Ron
 
Bought it over a year ago thru EBay, so warranty is invalid. Only if bought thru a Authorized EVGA retailer, does their warranty count, and they are not transferrable !
 
Do the other voltages change also?

What's the timing of the voltage changes? Is anything else changing when the 12 Volts does?
 
CPU 105W
GPU 250W
Motherboard 100W (typical allowance)
Drives 10W each
Fans 2W each

Roughly 500W or so with maximum possible CPU and GPU loading. The power with everything idling at the desktop will be a fraction of that.

I'd say the PSU is simply far!!!! to big and the load on the 5V rail is too low for the other rails to stay within tolerance when the machine is idling.

PC PSUs generally only have a limited load range where they can stay within all tolerances. I've seen similar problems before when people use massively oversize PSUs.

A 650W from a good maker would be more than sufficient.
 
Well the Nvidia 1080ti Cards were made very power hungry, and since the prices are dropping on those I was planning on getting a second one, plus adding another pump to power two loops, vs one loop. It never got around to it. It has been running flawlessly until just recently when my WOW game would cause my HDMI to shutdown after about 15 to twenty minutes of play, which started happening shortly after I was noticing the voltage drops, on the 12v rail ;-()
I also got a fair deal when I bought the power supply, so at the time I was happy with it./ I just was wondering what defect with it would cause it to do that, since I do have some electronics background and was possible to repair it myself ?\
 
While I still believe faulty supply since it is a modular design make sure all connections are secure and tight. If it starts out OK and after a period begins to fail to regulate it could be a heat issue but that goes back to the PSU. I see a new PSU in your future.

Ron
 
I would never rely on motherboard sensors for voltage readings via software. Use a real voltmeter and measure the voltages at the video card add-on power plugs (PCIe) and the extra +12V plugs for the CPU (EPS/ATX/?? plugs).
 
sagor1 said:
I would never rely on motherboard sensors for voltage readings via software. Use a real voltmeter and measure the voltages at the video card add-on power plugs (PCIe) and the extra +12V plugs for the CPU (EPS/ATX/?? plugs).
Click to expand...
That's a good point. I originally assumed you were using a known good reliable meter to get the measurements and the system was failing. If the system is running fine then I would not rely on any onboard software or hardware.

Ron
 
So, did you just decide to monitor the voltage and you saw an occasional 10.8v reading, or do you have an actual issue with performance or other?
 
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