PC doesn't boot with ATX 12V cable attached

[pepboom]

Earlier today, I turned my PC on and left it for a couple of minutes so I could grab breakfast. When I came back, it was off and couldn't turn on again.

 

Naturally, I was panicking since this is my first time with an issue like this, so I started to Google some potential fixes for this.

 

I figured it was a PSU issue, so I did the classic paperclip jutsu just to see if it works in the first place, then started to plug things one after another and try turning the computer on. One after the another, it all worked fine.

 

I was happy, thinking that maybe keeping the battery out of the motherboard for a couple of minutes while I was trying to pull some theory crafting worked.

 

Then, like a movie scene, just while I was bringing the computer back to my desk to set everything back up, I saw it.

 

Those yellow-black cables and that 4 pin plug.

 

Dangling out in the air.

 

I slid it right back into the socket, and there it was again. No dice.

 

I'm praying to God it's not a motherboard issue cause I currently do not have the money or patience for a replacement, considering it's one of those dreaded pre-built computers I got for a decent price.

 

If anyone has any idea what the issue might be, help a fella out. I'm this close to biting the bullet and giving it to a computer store for any fixes possible.

[Alvin853]

You don't happen to have a multimeter? Sounds like something is shorting out on the 12V EPS connector. The PSU will detect the high power draw immediatly and go into protection mode. You might see a very short blink of LEDs or a tiny bit of fan movement before the protection kicks in.

 

Without some tools it's going to be near impossible to diagnose what the problem is. You could look at the area around the connector, make sure it's all clean and there's no dust or anything that could make a connection. If it's a problem with the board, fixing it will probably cost you more than replacing the entire board. If you see an obviously blown capacitor, you can try removing it and running without, but anything else will require soldering.

[pepboom]

20 minutes ago, Alvin853 said:

You don't happen to have a multimeter? Sounds like something is shorting out on the 12V EPS connector. The PSU will detect the high power draw immediatly and go into protection mode. You might see a very short blink of LEDs or a tiny bit of fan movement before the protection kicks in.

 

Without some tools it's going to be near impossible to diagnose what the problem is. You could look at the area around the connector, make sure it's all clean and there's no dust or anything that could make a connection. If it's a problem with the board, fixing it will probably cost you more than replacing the entire board. If you see an obviously blown capacitor, you can try removing it and running without, but anything else will require soldering.

I don't have a tool to check voltages or something similar.

 

You are correct about one thing: The side fans spin for a tiny bit when I try to turn the computer on with the cable attached. I probably should have mentioned it beforehand.

 

The spot is pretty clean, doesn't look like any bits of dust would be able to stop the connection in some way.

[Alvin853]

What's the motherboard and CPU? How easy would it be to remove the CPU? 

[pepboom]

6 minutes ago, Alvin853 said:

What's the motherboard and CPU? How easy would it be to remove the CPU? 

The motherboard is the disgusting-looking Medion B360H4-EM with an I5 8400. I haven't ever attempted to remove it before, but doing so shouldn't be a huge issue.

[Alvin853]

It's probably the best to have a professional with the right tools take a look at it. Some things you can do yourself:

Remove the RAM, and try to turn the PC on. Yes it won't boot without RAM, but if the fans stay on longer, you know the original problem was related to RAM.

Do the same thing for the CPU, remove it and turn the PC on. If it stays on, the issue is still most likely the motherboard, but that at least greatly reduces the possible problems and could end up being easy to fix. 

If neither of those options change anything, it's just a dead board and a new one will be cheaper than trying to fix yours.

[Kilrah]

Does suggest the mobo could have died and be causing a short on the EPS input, fans spin a tiny bit at power up until the PSU detects the short and turns itself off.

[pepboom]

18 minutes ago, Alvin853 said:

It's probably the best to have a professional with the right tools take a look at it. Some things you can do yourself:

Remove the RAM, and try to turn the PC on. Yes it won't boot without RAM, but if the fans stay on longer, you know the original problem was related to RAM.

Do the same thing for the CPU, remove it and turn the PC on. If it stays on, the issue is still most likely the motherboard, but that at least greatly reduces the possible problems and could end up being easy to fix. 

If neither of those options change anything, it's just a dead board and a new one will be cheaper than trying to fix yours.

Just did what you asked:

 

Again, the problem seems to be solely dependant on that one slot alone. If its unplugged, it turns on with and without the RAM attached. The same with the CPU.

 

When I start it up with the plug attached, it merely twitches with life before stopping completely. I'll look into a checkup and see if it's going to be worth it. If not, It's gonna be painful for my tiny wallet. Looks like I have little choice regardless. Thanks for the help.

[Alvin853]

3 minutes ago, pepboom said:

Just did what you asked:

 

Again, the problem seems to be solely dependant on that one slot alone. If its unplugged, it turns on with and without the RAM attached. The same with the CPU.

 

When I start it up with the plug attached, it merely twitches with life before stopping completely. I'll look into a checkup and see if it's going to be worth it. If not, It's gonna be painful for my tiny wallet. Looks like I have little choice regardless. Thanks for the help.

The upside of this is: at least it seems "only" the board is broken, and hopefully RAM and CPU are fine. Try finding a cheap B360 board on ebay or something, I don't think they're being produced anymore so getting one new will be expensive.

[pepboom]

11 minutes ago, Alvin853 said:

The upside of this is: at least it seems "only" the board is broken, and hopefully RAM and CPU are fine. Try finding a cheap B360 board on ebay or something, I don't think they're being produced anymore so getting one new will be expensive.

Could only find one listing for 90 euro, this is going to be a painful one.

[pepboom]

Leads into a new question:

Do I have to get the exact same motherboard as a replacement, or do any B360s work in here?

 

If it isn't obvious enough, I'm not too experienced with this.