[SOLVED] PC restarting with black screen: faulty PSU or Asus Mobo?

TomPlk

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Hi, over the past week my PC has been randomly restarting and rebooting with a black screen. The monitor is still on, the fans still run, but it wouldn't boot up until I opened the case and allowed it to cool down for a bit. So I assumed it was an overheating issue for either my CPU or GPU. It restarted during a videogame, and once when I had three tabs open on my browser.

I opened the case and cleared out the dust with compressed air.

Then this morning, my PC restarts itself after just logging on and browsing emails. It reboots with this message:

"Power supply surges detected during previous power on. Asus Anti-surge was triggered to protect system from unstable PSU".

I only bought my Seasonic PSU October last year, and it's been working fine. But I don't want to switch off Asus Anti-surge in case it really is protecting my PC from a faulty PSU.

And just now, my PC screen just went black without even bothering to restart (monitor still on). I had to switch on and off at the mains, and now it's working again.

Is there a way to figure out if it really is a faulty PSU? Or is Asus anti-surge being over-sensitive? Maybe it's something to do with the powerstrip I'm using?

Thanks.

Specs:
OS: Windows 10 64-bit
CPU: AMD FX-4350
16GB RAM
Mobo: ASUS M5A78L-M/USB3
GPU: AMD Radeon R7 200 series
PSU: Seasonic Focus Plus Gold 550W (80+ Gold ATX 12V)
 

SteveRX4

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I'd vote for the upgrade. The FX4350 was always weak and now is very very old. When things are that old they commonly start breaking down and it's hard to do repairs or get replacements.

But try changing power leads is a good idea.
 

TomPlk

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I checked the temperatures when my PC was idle, and it didn't seem to be overheating. My PC didn't even have a chance to get hot when it restarted this morning. All I did was open my browser. I felt the side of the case as soon as it turned off, and it was pretty cool. (not the most accurate measure, I'm guessing.)

I tested the PC yesterday with a game that has made my system overheat and crash in the past, and it worked fine.
 

TomPlk

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Just tested it with Core Temp. On idle, running nothing more than a Word file, it went from 12-20 C.
While playing a game, it went up to about 40C

The cooler is just the standard heatsink that came with my CPU.

I'm not against doing a BIOS reset if I have to, but I don't want to mess around with the BIOS if the cause is just an oversensitive mobo reacting to a power surge. Or something else.
 

TomPlk

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So I just got back from work, and I turned on my PC. It wouldn't boot up at all. Fans are going, the monitor power is on, but just a black screen.

I unplug at the mains, detach the mouse and keyboard and turn it back on. Nothing.

I power it off again, and unplug the speakers. Still nothing.

So I unplug it, open up the case, and shine a torch in there to see if there is any burnt out compenents. Can't see anything, but it's dusty. So get out a can of compressed air, blow out the dust, including over the CPU heatsink. And then it boots up fine.

A few minutes later it powers off while I wrote this post. No restart. I power off at the mains and turn it back on again, and now it's fine.

Does anyone have any idea what's going on?
 

SteveRX4

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Do you really think your CPU would've been at only 12C?
Try say HWInfo 64 to get CPU temps.
What cooler are you using on the CPU?
Can you do a bios reset?
If you remove the gpu, will it post? (Have you got a motherboard speaker attached?)
 

TomPlk

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I'm clearly not an expert, I don't know what normal CPU temperatures are. But I downloaded HWInfo64, and the CPU temperatures I'm getting at the moment are:
Min: 35C
Maximum: 43C
Average: 40C

While gaming for a bit, it came to 50C, and the following:
Min:36C
Max:51C
Average:45C

I checked the CPU cooler again, and it does just look like the heatsink that came with my CPU. It just has the AMD logo. I don't know, this system was put together years by someone else (probably around 2014-2015, so it's not new). It looks like this (last image in the image gallery)

I have never done a BIOS reset, but having googled the instructions, I would be happy to try if necessary.

I haven't tried removing the GPU yet, I won't have the time today. Maybe tomorrow.
 

SteveRX4

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The temperatures are OK. So the CPU and cooler should be OK

What about the PSU voltages in HWInfo64 - 3.3V, 5V and 12V - max and mins?
Seasonic are about as good as you can get but let's just check anyway.

New motherboards have a button to reset bios (cmos).
You'll have to do it like - https://neosmart.net/wiki/reset-bios-cmos/
I think cmos is an extension in bios where your changes that you made are stored. The bios chip just holds what you downloaded onto the motherboard. This reset gets rid of any changes that you've made.
 

TomPlk

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Hi, sorry this took a while. Weirdly, my PC has been working fine since Wednesday night (fingers crossed), no problems. Maybe it was just a power surge?

Here are the PSU voltages into the mobo from HWInfo64.

3.3V Max: 3.404V Min: 3.384V
5V Max: 5.040 Min: 4.860
12V Max: 12.029 Min: 11.951

Thanks for the instructions on BIOS reset, but if my PC is working fine for now, I don't want to mess around in the BIOS. If the problem occurs again, then I will reconsider it.
 

TomPlk

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Sorry to bump this, but it doesn't seem as though my issue has resolved itself like I hoped.

My PC has been working fine all week. It was working fine this morning. I just got back from work, turned it on, and it's back to black screen.

The monitor turns on, the fans are going, but there is no beep sound on start up and the screen is black.

I restart it several times. I have just opened the case for the second time, and cleaned it thoroughly with a can of compressed air. The second time I pushed in the GPU, the RAM, and the network card, although only the network card felt like it was out of place.

Now it starts up.

If this was the GPU, could the PC still at least boot up using the integrated graphics on the mobo? (although after some googling, I hear that there is no Windows 10 driver for the integrated graphics on this mobo).

The RAM seemed to be firmly in place, and I'm not sure how a loose network card could cause a failure to boot.

Could it be the PSU?
 

TomPlk

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If this was the GPU, could the PC still at least boot up using the integrated graphics on the mobo?

Can you put a motherboard speaker on your motherboard? It should emit a boot code when you start your PC up. If everything is OK then it'll just beep once.
See https://www.computerhope.com/beep.htm
Most Motherboards have an AMI bios.
Yes, my motherboard has a speaker. It normally beeps once when it boots up. When it doesn't boot there is no beeping at all.

I just tested my PC without the GPU in, and yes, it can still boot up without a GPU. However, when I shut it down, it restarted with another power surge error message. I have just reinserted the GPU and started it back up fine though.

I did notice that my GPU fan was caked with dust. I thought I was on top of cleaning the dust out of the inside of my case, but I guess not. I cleaned the dust off before reinserting it.

Today however, it has been playing up constantly. During the day it would continually shut down and restart with the same error message about power surges, brougt on by my Asus mobo anti-surge protection.

This time I went into the BIOS and took note of the Vcore voltages:

Vcore Voltage: 1.334V
3.3V: 3.363V
5V: 4.800V
12V: 11.951V

I don't know if that's of any use, but I thought I should take note of it.

I've got a feeling that my PC is just getting really old, but it would be useful to know if a single component besides the mobo is causing this.
 

TomPlk

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The voltages are OK. But not as good as I'd think with a Seasonic PSU.

What was the power surge error message?

Are you using a UPS?
The same error message as further up the thread: "Power supply surges detected during previous power on. Asus Anti-surge was triggered to protect system from unstable PSU".

I'm not using a UPS, just a standard power strip that I've been using for ages without any problems.
 

TomPlk

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Thanks Steve. I've ordered a wall socket circuit tester on Amazon, should be here soon. I'll consider a UPS afterwards. I don't have another PSU to test it out on.

Interestingly, after 3 instances of my PC powering down this morning, I switched to another wall outlet and everything is fine so far. I have a feeling it might be the wiring in the house. But if it does give out again, then I'll have my answer.
 

TomPlk

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It gave out again. There's (part of ) my answer. It's probably the PC. The extension cord that plugs into it is ancient though, could that cause it somehow? Either way, I'm still testing my wall outlet.

Now, I'm definitely looking to a UPS and I'll check out the warranty on my PSU. I might just buy a whole new system, it's old anyway, I just need to rule out the wiring in the house.
 

SteveRX4

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I'd vote for the upgrade. The FX4350 was always weak and now is very very old. When things are that old they commonly start breaking down and it's hard to do repairs or get replacements.

But try changing power leads is a good idea.
 

TomPlk

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My replacement anti-surge extension cord came in the post today, so I replaced my old extension cord (the date on the back of it was from 1984.)

I tested the wall outlets this morning and they all checked out fine. It looks like either a PSU that went bad before it's time, or maybe some other component (probably the CPU I'm guessing).

Either way, I'm shopping for a new system right now.
 

SteveRX4

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OK. You should ad [SOLVED] to the left hand of this thread heading so that a Mod will close it.
If you want advice in choosing your next system, just start another thread. Have fun shopping.
 

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