Question Idk how i fried my board need help

Jun 28, 2022
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So I've had my Pc for about 6 years its a prebuilt I've never taken out any parts or messed with anything since i got it in the mail its been a beast and everything ran awesome all this time with no problems playing any game on it. But last week i needed to use my printer and long story short, The pc was already running and i plugged the usb part of the printer in the motherboard on the back of the pc where i plug all kinds of other stuff just fine, then i plugged the power chord of the printer into a outlet and boom sparks flew and the computer shut off and now it wont turn back on whatsoever. I took it to a shop cause I'm not a crazy computer wizard kinda guy but they told me the motherboard was fried but all my other components are safe and still working only thing they didnt check was the power supply for whatever reason. Can anyone shed some light on why this happened so i can prevent it from happening again? or maybe salvage or re test the motherboard to make sure the people at this repair shop are telling the truth?
 
Certainly an interesting case, since nothing of what you did was inherently wrong.
Most likely situation, its the printers fault, something internally shorted out and send a surge of power through the USB to your system.
Motherboard is likely fried, as you suspect, I personally wouldnt try and use it again. Depending on the protections on the motherboard specifically the rest of the system should be alright, but theres no way to know for sure. Most likely damage next would be processor/RAM, then maybe the PSU (which you can have tested if youd like).
 
Jun 28, 2022
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i can supply more info if anyone has any questions on specs or certain details of the incident. The printer is a few years old but still like new I don't think I've used it more then 5 or 6 times its a small laser brother printer I've used it on my computer before I most likely had it plugged either in the same usb port or a diff one cant really remember but ive used it with my pc before just fine .. The printer actually is dead now it doesn't even turn on or anything i tried diff outlets and nothing. The guys at the shop did show me a spot on the board where it could of fried said something about some Sauder the was exposed i could take a picture of the area and spot on the board for people to see. I was just going to buy the exact same board and replace it myself since it should be easy plug and play just afraid of something like that happening again
 
Go ahead and post the pictures, they are always nice to have.
Replacing it with the same board is a safe bet, but you should reinstall windows. It might work out of the box, but you will typically run into issues with a new board and an old copy of windows.
 
Jun 28, 2022
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really even with the same motherboard and same windows and everything? nothing would change i would just be taking old motherboard out and putting the exact same one in just new.. i will post pictures later tonight for sure!
 
Yeah a small portion of windows is actually tied to the motherboard, so when you replace it windows has to "fix" that missing piece.
Sometimes it gets it right and the system works, other times (most of the time) there are some small issues with drivers and things like that. Something small, where it would take longer to troubleshoot than just reinstalling windows.
The system would probably work with the direct replacement, but who knows when the issue may come up?
 

jasonf2

Distinguished
USB ports are by design both signal carrying and also capable of supplying power (IE phone charging). That mixture of the two can lead to major machine damage when errant voltage is applied. The biggest vulnerability is when the ground has high voltage applied directly to it. For the biggest part grounding in computers is really there less for safety (Which is why we have the third pin on the plug in the first place.) and more for a zero volt reference. When stray voltage is applied to any ground path in a computer the ground traces aren't built to carry any real amperage and pop relatively easily. Once a trace burns then the zero volt reference for the other things downstream from the open circuit is removed. This causes on board voltage regulators to float and switching power supplies to incorrectly produce voltage. The whole thing is a really bad combination when it happens and you can see damage to the system that at first glance doesn't make sense when you just sparked a USB. Lightening can do the same thing, especially over wired communication links between different buildings that have separate meters and ground stakes. I would throw that printer away.
 
As said, what you did shouldn't have been an issue. Curious about you saying 'sparks flew'..where exactly? Most motherboards protect usb connections from overdraw and shorts..what motherboard is it, and also what power supply is in the PC, and what printer? Pics of the solder issue on the motherboard would be helpful. Also, if you do end up replacing the mobo with the same make/model/ and version with what you have now, Windows should be fine
 
Jun 28, 2022
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i can post pictures of everything over the weekend since that is when ill be tearing the computer apart to clean it and re do cable management and change the mobo . Psu is a 850 wat evo plus gold edition i think ill be doing the paperclip test to see if it works. But the printer is just a basic laser printer from Walmart the brand of the printer is the "brother" I've used it in the past with the same pc less then a dozen times the printer doesn't work anymore after the incident. And when i mean sparks flew sparks flew from the outlet where i plugged the power chord of the printer like the prongs from the printer chord have slightly melted tips like they are burnt. The usb part of the printer where i plugged into the computer looks fine nothing melted or damaged maybe like a small amount of some kind of black residue maybe like glimpse of a burn mark in the usb plug but not sure. im just afraid for something like this to happen again with my new mobo or a future build scares me to plug anything into it now lol
 
nd when i mean sparks flew sparks flew from the outlet where i plugged the power chord of the printer like the prongs from the printer chord have slightly melted tips like they are burnt
im just afraid for something like this to happen again with my new mobo or a future build scares me to plug anything into it now lol
Make sure electrician checks that outlet. To me it sounds like it may be source of your problem.