Question I messed up my computer.... wonder what went wrong

[corbieristan]

So i have this old computer from 2015 that i had build at the time and i was looking to sell it to a friend for cheap(it was working flawlessly until today...). I wanted to add a fan and put new thermal paste, which i did today. it worked fine for an hour, then it shut down on its own. I started it again, and 5 minuts later it shut down again. Only this time time it wouldn't start. No fan, no beep, but the led on the motherboard was lit.
I tried to understand what was going on and to make things worse, i foolishly pushed a button on the power supply unit, thinking it wouldn't hurt because the computer wasn't turned on and it actually changed the voltage to 115 and fryed my psu.....

Needless to say i feel like an absolute idiot today. I was probably too tired to do stuff but i tried anyway. My psu was rather high quality and i have a few questions:

1. What went wrong initially to cause this issue? i think it's either linked to the processor or the additional fan... probably the processor. I did a put a bit too much thermal paste.
2. is the motherboard/cpu dead after the psu incident? There was just a spark in the psu and it went off.
3. How hard would it be to fix my psu by changing parts? or maybe just a fuse? it was a xilence xp420. i'm really angry at myself and i'm considering taking a day to fix this. But then i have also the starting issue!

I really would like to fix my mistakes, the hard drive is working perfectly at least. i couldn't test the rest, i don't have the material required.
Any help is appreciated

 

[DRagor]

What went wrong initially to cause this issue?

Sounds like you messed up with CPU cooler installation and system shut down due to overheating. Obviously not possible to tell what exactly you did wrong. However if it was the case then turning the system up again when it turned off might have cooked the CPU.

is the motherboard/cpu dead after the psu incident? There was just a spark in the psu and it went off.

Quite possibly yes. No way to tell what died until you get new PSU and try.

How hard would it be to fix my psu by changing parts?

If you have to ask you are not qualified to do it. Anyway I'd say 99% chance PSU is just dead.

it was a xilence xp420

This days anything that still has voltage selector button is as low grade PSU as it can get. Xilence has never had any high quality units anyway.

 

[Nate88888]

1. From the information you have given about how you added too much thermal paste, potentially the thermal paste could have leaked onto the motherboard and caused a short in the motherboard potentially causing the PC to switch of and possibly causing damage to the motherboard. Whilst unlikely it could have possibly been a weird issue with the fan or fan header on the motherboard especially if the fan was of a generic brand. I find it hard to think that if the CPU cooler was applied correctly it would overheat unless it was a silly CPU and CPU cooler combo.

2. There is a chance it is damaged, the better quality the PSU and motherboard the less likely it is damaged however there is no way to know unless it is tested.

3. It is not recommended to try to do a repair on a PSU without experience as you will be risking damage to the components and you can buy a higher wattage EVGA power supply for about £40 anyway.

 

[corbieristan]

1. From the information you have given about how you added too much thermal paste, potentially the thermal paste could have leaked onto the motherboard and caused a short in the motherboard potentially causing the PC to switch of and possibly causing damage to the motherboard. Whilst unlikely it could have possibly been a weird issue with the fan or fan header on the motherboard especially if the fan was of a generic brand. I find it hard to think that if the CPU cooler was applied correctly it would overheat unless it was a silly CPU and CPU cooler combo.

it does make sense. This is not my first time doing this, and the fact that it worked for an hour makes me thing it's something like that... maybe with the heat the paste leaked somewhere it shouldn't have...
Anyway will probably sell all this for cheap to someone who knows...

Sounds like you messed up with CPU cooler installation and system shut down due to overheating. Obviously not possible to tell what exactly you did wrong. However if it was the case then turning the system up again when it turned off might have cooked the CPU.

There was no warning of any kind. this isn't my first time doing this and i think i did this correctly, except for the amount of thermal paste..... which might or not be the issue. The cooler and its fan were firmly sticking to the cpu when i unmounted it to see what went wrong

If you have to ask you are not qualified to do it. Anyway I'd say 99% chance PSU is just dead.

A bit condescending, that could be an opportnuity to learn.

View: https://www.youtube.com/watch?v=Fupi_bHwKLQ&t=181s&ab_channel=DiodeGoneWild

 

[DSzymborski]

it does make sense. This is not my first time doing this, and the fact that it worked for an hour makes me thing it's something like that... maybe with the heat the paste leaked somewhere it shouldn't have...
Anyway will probably sell all this for cheap to someone who knows...


There was no warning of any kind. this isn't my first time doing this and i think i did this correctly, except for the amount of thermal paste..... which might or not be the issue. The cooler and its fan were firmly sticking to the cpu when i unmounted it to see what went wrong



A bit condescending, that could be an opportnuity to learn.

View: https://www.youtube.com/watch?v=Fupi_bHwKLQ&t=181s&ab_channel=DiodeGoneWild

It's not condescending; this is dangerous work, and repairing a power supply is not part of Electricity 101. Ethically, we do not encourage people to do things that are dangerous that they're not qualified to do. That you didn't know what the voltage switch would do is an indication that you do not have remotely the level of backround knowledge necessary to fix a power supply competently and safely. Learning is always good, but you should be seeking books, maybe a class, and doing something like taking apart and reassembling/rewiring an old lamp, not playing with a PC's power supply.

This power supply is group-regulated junk anyway, and the fact that it has passive power factor correction already suggests that this is junk from about 15 years ago. It's not worth fixing since it's not worth using in the first place; from the point of view of the PC, it being completely non-functional is the ideal status since it can't do any damage. Hopefully it's journey to the grave didn't involve taking any of the mystery parts with it (it's hard to say more since you didn't tell us anything about your PC).