Question Issues with PSU, computer will occasionally lose power but only when it is off.

[wid151]

I built this PC several years ago, and had zero issues for the first few years of useage. Lately however I have been encountering an issue where my PC will not turn on. I know this has something to do with the power supply as my GPU has a power indicator LED whitch is always on when it has power. When the PC is powered on it functions as normal and does not lose power. It may fucntion as expected for hours, days or even weeks between issues. I have tested the PSU by shorting it with a paperclip, PSU powers on as expected. I further tested all the pins on the 24 pin ATX connector using a multimetre. Again, everything worked as expected. I am at a loss to explain the intermittent power loss, there does not appear to be a discernable pttern.

 

[Inspireless Llama]

What PSU is it? Brand and wattage?
What are the specs of the rest of your PC?
What do you mean by not turning on? Doesn't it do anything, does it not POST, does it not reach the mobo logo?
When booting, does the mobo ever give error signals if you're able to receive them?

 

[wid151]

Sorry, should have provided specs. They are as follows:

Case: Thermaltake View 71 Tempered Glass Edition
PSU: Thermaltake Toughpower 750W Gold (Modular)
CPU: AMD Ryzen 7 2700X Eight Core processor 3.7GHz
Motherboard: MSI X470 Gaming Plus
GPU: Asus Strix Geforce GTX 1060
RAM: G.Skill Ripjaws DDR4 2800mhz 2X 8GB
And by not turn on I mean there is no response from the PC, it acts the same as if it were unplugged from power. Aside from this one issue I have zero other issues, no mobo error signals of any kind.

 

[Inspireless Llama]

To me that indeed sounds like a PSU. I'm no PSU expert though. First 2 things I can ask you to try (if you can) are trying a different power cable and a different wall outlet to exlude these 2 things for a lack of power.

@Oussebon since I see you arround most with PSU's, interesting in seeing if you can help with the issue?

 

[wid151]

Yeah I swapped the IEC out and tried in a different room of the house. Same issue. The only thing that ever seemed to make a diference was pulling out the 24 pin connector from the mobo and then plugging it back in again, which I have read may be a sign of static build up. But this does not always work. I am utterly perplexed.

 

[Oussebon]

Well outwith my experience I'm afraid; the furthest I go with PSUs is trying to get people to neither under nor over spend on them

When the PC doesn't power on, are the LEDs on the motherboard that are normally lit when the PC is off but has power lit?

 

[wid151]

My motherboard does not have any LEDs that are lit when the PC is off but functional, only my GPU. But when the PC is not powering on, that GPU LED is off. Hence I am pretty certain it is a power issue between my PSU and motherboard. What I cannot explain is why it is so random.

 

[Kaamos_Llama]

Random electrical faults are always fun to replicate.

I did find something interesting here. Try disabling Fastboot or Faststartup in BIOS and see if that helps.

Otherwise I guess it could be the 24 pin cable as well as you mentioned that, try swapping that out for a spare if you can find or borrow one too.

Unfortunately the only way to know if its the PSU for sure is to check with a known working one. So if there's one you could borrow from a friend do that. You may have to buy a new one or if you can wait RMA your one, sorry to say.

If it continues after that I'd assume you have an issue with your mobo.

 

[wid151]

Random electrical faults are always fun to replicate.

I did find something interesting here. Try disabling Fastboot or Faststartup in BIOS and see if that helps.

Otherwise I guess it could be the 24 pin cable as well as you mentioned that, try swapping that out for a spare if you can find or borrow one too.

Unfortunately the only way to know if its the PSU for sure is to check with a known working one. So if there's one you could borrow from a friend do that. You may have to buy a new one or if you can wait RMA your one, sorry to say.

If it continues after that I'd assume you have an issue with your mobo.

 

[wid151]

Oh so much fun. I work as a theatre tech so misbehaving electrical components are an old friend. I will try disabling Fastboot next time I get it to work, it is not turning on this morning. Should that fail I will try and source a new PSU from somewhere, I loooked at buying a new one the other day and there are month long delays with shipping down here in Aus.

 

[wid151]

UPDATE: I Have replaced the PSU and all asociated cables. Computer is now totally non-functional. Even unplugging and repluggin the ATX cable, which previously worked about 60% of the time is unable to restore functionality.

 

[Oussebon]

Assuming the new PSU is confirmed to work, I'd suspect the motherboard and contact MSI for troubleshooting and possible RMA.

 

[Kaamos_Llama]

Oh man, sorry to hear that. I hope the motherboard is still in warranty. My guess would be Australian temperatures over the years could have caused some extra heat wear on the power delivery.

I found this review of your motherboard, that shows it doesn't really have the best VRM setup, FWIW. I know it doesn't help you right now, but this is the reason I like to recommend motherboards with better then basic VRM's. MSI pulled a really sneaky one with this board though so it would be hard to know.

I've heard that you can test for VRM failure by leaving unplugging the CPU power plug and powering up with the 24 pin still plugged in. If you get any signs of life (LED or fan spinning up) then it's the VRM. I'll add a disclaimer this is just something I read though.

 

[wid151]

Just fired off a report to MSI, hope they get back to me. Thanks for all your help, I think I am reaching the point where the only option is a new motherboard.