PC surging power to keyboard after switching mobo

Ricardo56 · April 30

Yesterday I swapped out my B350-F for a second hand X570-Pro, and I even played some games for a while with the new setup, but today, shortly after connecting my powerbank to the front usb connector with the pc turned off, my girlfriend was trying to turn on a light switch near the computer and the lightbulb apparently exploded/started smoking. Then the peripherals (namely keyboard and speakers) started blinking as if they were trying to turn on, so I disconnected the PSU and monitor, then the extension cord which powers both, but the lights kept blinking (also one red light in the top left corner of the mobo, which I’m not sure could be related to the 8 pin connector for the CPU?).

From what little I read it could be the motherboard surging power, but I’d like to know how to proceed from here. I’ve disconnected all peripherals and was wondering if I should disconnect the CMOS battery, but I thought it’d be better to ask the forum first before I wreck my pc any further.

Thanks in advance!

Sawa Takahashi · April 30

What happened is most likely a power surge from the electrical system of the house. Not much can be done about it except call an electrician and contact the power company.

As for your PC, it doesn't look good but maybe you can save some parts. Computers have many layers of protection so it is likely something survived despite the light show.

If you don't like or want to work on your PC components, you should ask a friend or a repair shop to do the following suggestions in your stead.

First, don't plug your PC. That is a safety precaution and to prevent further damage.

I'd completely disassemble the PC and remove the parts from the case. Remove all cables and even remove the RAM, the CPU and the GPU from their sockets.

Set the motherboard and PSU aside for later.

Next step is to test every component one by one in another computer to rule out which one is defective and which one is still working.

The PSU can be tested but if I were you I'd simply never use it again. If it is still working, it probably became more unreliable due to the surge it experienced.

As for the motherboard, if no other components did burn then you can try assembling the computer again. If other component failed then I'd assume that the motherboard suffered damage too and it may be for the better if you change it.

Hope that helps.

Ricardo56 · April 30

1 hour ago, Sawa Takahashi said:

What happened is most likely a power surge from the electrical system of the house. Not much can be done about it except call an electrician and contact the power company.

As for your PC, it doesn't look good but maybe you can save some parts. Computers have many layers of protection so it is likely something survived despite the light show.

If you don't like or want to work on your PC components, you should ask a friend or a repair shop to do the following suggestions in your stead.

First, don't plug your PC. That is a safety precaution and to prevent further damage.

I'd completely disassemble the PC and remove the parts from the case. Remove all cables and even remove the RAM, the CPU and the GPU from their sockets.

Set the motherboard and PSU aside for later.

Next step is to test every component one by one in another computer to rule out which one is defective and which one is still working.

The PSU can be tested but if I were you I'd simply never use it again. If it is still working, it probably became more unreliable due to the surge it experienced.

As for the motherboard, if no other components did burn then you can try assembling the computer again. If other component failed then I'd assume that the motherboard suffered damage too and it may be for the better if you change it.

Hope that helps.

Yeah, that really sucks… I’m from Portugal so on Monday we got hit by that blackout in Europe and now this It really sucks because most parts were bought in November. The GPU, PSU and CPU are under warranty, but I’m not sure they’re covered if my house just decides to vaporize them.

Another detail I should add is before I switched my PSU, touching the case would give me slight shocks, so probably my outlet isn’t grounded and it was just a matter of time until something like this happened. Since this new PSU wasn’t shocking me throught, I thought it could’ve been solved.

Anyways, thanks for the tip, I’ll try to setup my old pc in a part of the house that might (?) have better outlets so I can test out the components

Sawa Takahashi · April 30

3 hours ago, Ricardo56 said:

The GPU, PSU and CPU are under warranty, but I’m not sure they’re covered if my house just decides to vaporize them.

That is worth a try. You can tell the manufacturer that your component(s) stopped working. No need to tell it was from a power surge unless they specifically ask.

Did you use a surge protector ? Those often have a warranty for the devices plug into them.

Good luck !

Sawa Takahashi · May 1

21 hours ago, Sawa Takahashi said:

What happened is most likely a power surge from the electrical system of the house. Not much can be done about it except call an electrician and contact the power company.

I just saw a youtube video from Anton Petrov and it seems that you experienced a country-wide power surge due to yet unknown factors. I am not familiar with how your country do things in that case but you may be able to claim some "natural disaster" kind of help.

Good luck !

Ricardo56 · May 2

On 5/1/2025 at 1:59 PM, Sawa Takahashi said:

I just saw a youtube video from Anton Petrov and it seems that you experienced a country-wide power surge due to yet unknown factors. I am not familiar with how your country do things in that case but you may be able to claim some "natural disaster" kind of help.

Good luck !

There was talk of being able to ask the power companies for compensation in case of appliances dying, but I’m not sure if it ever went through, because the companies could claim that it was beyond their power to do anything (with it being so mysterious and all).

Anyways, since everything was in warranty and the PC was off when it happened, I just took the risk and plugged it into a grounded outlet. I had to mess around with bootdrives in the BIOS a bit, because windows seemed to have some error finding essential files, now it’s golden!

I bought a surge protector for the ungrounded outlet until we get an electrician to come fix all the outlets thank you so much for the help!

*For anyone who might see this in the future, definitely do take the thorough route of checking the components individually, I just didn’t have any thermal paste on me*