Desktop wont turn on after unplugging

Siska

Hubby's is having a problem with his new desktop computer. When there is a power outage or he unplugs the power cord from the wall, sometimes it will not turn back on again after plugging it back in. No fans, lights or anything. It has happened twice now in 2 months. First time it was after a power outage (not a surge) and he pretty much disassembled the whole thing trying to figure out the problem. Made sure it wasn't switched off in the back. Tried a different power cord, removing ram sticks, switching the power button with the reset button. Tested with an old 500W PSU that he wasn't sure if it was even strong enough (or even worked) and nothing. Then he put everything back together in it's original state and it worked! No idea why it stopped or started working again. This was about 2 months ago.

Fast forward to today. We had a thunderstorm and he unplugged his computer from the wall, after turning it off. And it happened again. No light, fans or any kind of response after he plugged it back in. He again made sure it's not set to off in the back but that is about as far as he has gotten. He obviously does not want to have to possibly tear his computer apart every time there is a power outage or he unplugs it. IF that would even work again.

What might the problem be? Is there some easy way to check when it wont even turn on right now? Could the culprit be some very stupid bios setting or is hardware failure more likely? Any suggestion for how to get it to turn back on without picking it apart and putting it back together? Any ideas?

This is his computer. Most of it is new except for the case, the 240GB SSD and the PSU which are maybe 5 years old: Hubby's computer on PCPartPicker

Siska

Ok. Googling for suggestionst I saw it mentioned several times that turning the PSU off in the back, hold down the power button for 10 secs, turn the PSU back on and then try turning the computer on might work. First time it did nothing. Second and third time a light briefly flashed on the mobo ( might have been the one labeled EZ Debug LED ) and the PSU fan spun half a rotation and blinked on for a moment. But it did not last beyond that. Not sure if we should keep doing it. What is holding down the power button for 10 seconds actually doing and can it harm anything if you do it too much?

dispatch.o

Starting option - Open the case, disconnect the front panel connectors - all of them. Use a flat head screwdriver to short the power_button and see if it turns on.

It could just be the power button dying on the case front panel, or it's connected in a way that's causing a short. That's where I'd start.

Simplest solution first.


Edit: Yeah, I'd stop holding the power for 10 seconds. Cycling it hard like that won't help. That sounds like it's wired incorrectly or wired correctly and shorting/failing.

Edit2: If you don't go stabbing willy nilly, there's nothing on that set of front panel jumpers you're going to hurt by accidentally touching the screwdriver to them. Just don't go poking other things.

Skeith

If it's the BIOS popping out the CMOS battery on the motherboard might reset it, but I think you're at the point where you start pulling everything out and starting from CPU+RAM (one stick at a time).

Siska

dispatch.o wrote: »

Starting option - Open the case, disconnect the front panel connectors - all of them. Use a flat head screwdriver to short the power_button and see if it turns on.

It could just be the power button dying on the case front panel, or it's connected in a way that's causing a short. That's where I'd start.

Simplest solution first.


Edit: Yeah, I'd stop holding the power for 10 seconds. Cycling it hard like that won't help. That sounds like it's wired incorrectly or wired correctly and shorting/failing.

Edit2: If you don't go stabbing willy nilly, there's nothing on that set of front panel jumpers you're going to hurt by accidentally touching the screwdriver to them. Just don't go poking other things.

Ok, tried that. Did not work, as far as we can tell.

dispatch.o

Page 35 of the manual has the process and jumper location for clearing your CMOS settings.

https://www.msi.com/Motherboard/support/Z390-A-PRO#down-manual

Resetting BIOS to default values
1. Power off the computer and unplug the power cord.
2. Use a jumper cap to short JBAT1 for about 5-10 seconds.
3. Remove the jumper cap from JBAT1.
4. Plug the power cord and Power on the computer

Unfortunately it's a process of elimination thing now. Like Skeith posted above, you reset to CMOS defaults and then try to add one thing at a time starting with a naked motherboard and cpu.

Siska

dispatch.o wrote: »

Page 35 of the manual has the process and jumper location for clearing your CMOS settings.

https://www.msi.com/Motherboard/support/Z390-A-PRO#down-manual

Resetting BIOS to default values
1. Power off the computer and unplug the power cord.
2. Use a jumper cap to short JBAT1 for about 5-10 seconds.
3. Remove the jumper cap from JBAT1.
4. Plug the power cord and Power on the computer

Unfortunately it's a process of elimination thing now. Like Skeith posted above, you reset to CMOS defaults and then try to add one thing at a time starting with a naked motherboard and cpu.

Thank you. I'll see if I can talk him into trying that when he gets home. He is currently hoping it's just the PSU that has given up and is thinking of buying a new one. Apparently I imagined him trying a different PSU 2 months ago. He wanted to but we didn't have another one with compatible connectors. And he's actually think spiking his old PSU into the garbage can, before putting it back in is what might have fixed things last time, LOL.
Trouble with getting a new PSU is that he doesn't want to wait for shipping. Especially if it doesn't work. So he need to try and find some local store which might have one. Which I can't think of any except maybe bestbuy.

Skeith

Best Buy would almost certainly have something. I have actually had PSUs go bad because some bit of corrosion caused it to short somewhere (I live in a humid environment), so if you're in that kind of climate it could happen.

dispatch.o

Actually thumping a power supply can fix* one temporarily. So that wouldn't be that crazy.

*fix being temporarily make work until it shits the bed and thumping does nothing.

Mugsley

I had similar experiences and it turned out to be a bad video card. Considering you had a power outage and then later a thunderstorm that showed the same symptoms, I'd try that.

Do you have a known-good card you can use? If not, get the cheapest card from your local electronics store and return it if that's not the problem.

Edit: keep the GPU the same (Nvidia/AMD)

Mugsley

Also if you're (still) using the same surge protector or power strip, that could be the issue.

Cambiata

Mugsley wrote: »

Also if you're (still) using the same surge protector or power strip, that could be the issue.

Yeah I'll be honest my first thought was, are you testing different outlets when this happens? Especially if it happens after a storm, depending on where the outlet lays in your house, it could be getting wet during the storm temporarily shorting it out, then when it dries the outlet works again. Easiest way to test this is by putting something else in the outlet and seeing if it's showing power or not.

Siska

He took his computer to a local repair shop that does diagnostics for free. They tested the PSU and it does indeed seem to be dead. They also plugged in a test PSU and lights turned on and things were spinning. Unfortunately they did not have any PSUs in store to my hubby's liking so he could not get the whole thing fixed today. So he ordered one from Newegg that will take 2 weeks to get here... maybe. He's planning on calling around local stores on monday and see if he can pick one up, somewhere. If not, we will see in 2 weeks if all is truly good.

Thanks everyone!

Skeith

See if you can find the same model on Amazon. I've had good luck with them (Newegg reams me on shipping).

RoyceSraphim

Check USB ports to make sure they are not damaged. Lost months in repair work because I did not see the problem that could be fixed with a butter knife and scotch tape.