I think I killed my PC

[cubusmedusa]

I am afraid I killed my pc. But not with what was predicted to happen. No OCing.
I had my pc running with default settings and just wanted to find a way to measure the Vcore manually with a DMM. Since my cheapo mobo does not offer an easy way I thought to measure the voltage directly on the mosfets which worked perfectly. Until the moment I accidentaly touched the middle pin (which is not connected to the mobo) while connected to another pin on the mosfet.
The pc immediately went off and I cannot switch it on again.
So I am not sure what I killed because after the incident I unpluged the 12V ATX connector to measure the voltage that comes from the PSU.
What should I expect when pc is off? Is still 12V applied to the plug coming from the psu? Because I measure 0.2V.

Chris

 

[EarthDog]

If I was you, I would put down the DMM and walk away... LOL! I am not sure what that 12v should read when it is off... nothing or very low like you are reading would be my guess.

Being serious, you may have killed the mobo. If you jump the PSU does it (PSU NOT plugged into your PC) turn on? Do you have another PSU around to try in the system?

 

[cubusmedusa]

Thanks for your quick reply! I followed your link and the following happend.

I detached the 24pin connector while having the 12V CPU rail connected to the mobo. Jumping did not start the psu. Then I detached the CPU rail as well and the psu started.

 

[EarthDog]

Yeah, I said to unplug it from the PC... LOL! You are dangerous!

Sounds like you may have killed the CPU or mobo or both in this case. I am not sure how to test the CPU or mobo without testing it in another system.

EDIT: Time to upgrade!!!

 

[peanutbudder]

I would say you most likely killed the mobo and cpu which sucks but hey now you can upgrade.

 

[cubusmedusa]

I checked the 12V rail while PSU on. Delivers 12V so PSU should be ok.

 

[bamato]

It's not just the 12V rails I'd worry about. Did you test the other rails, or can you have someone else check them (you+electricity=disaster apparently )?

Do you have friends with computers that you can test the CPU in? Without the proper tools, I'm not sure you can test the mobo properly.

 

[cubusmedusa]

You cant make an omelett without breaking eggs.
Thanks for your help.
Pitty. this mobo survived so many things but things happen.

 

[Spreco]

I'm pretty sure that your motherboard and PSU are both dead. Take your DMM and measure the voltage between green and one of the black wires, it should be 5V.. If it's anything other than that, count it as dead. If it is 5V, jump the PSU (unplug EVERYTHING from the motherboard, connect the green and one of the adjacent black wires with a piece of metal, clipper would work best, don't worry about those harmless 5V). If it jump starts and you hear the fan then you need to measure all the voltages in the 24-pin connector according to this. The tolerance should be between +-5% and +-10%. If all the voltages are okay, then your PSU is fine. As for your CPU and motherboard, I think they're both dead. You need to test them with other components. I also had a problem with a cheap PSU which fried everything besides my graphics card so I just replaced it (it was a cheap replace anyway as it is an old but yet powerful PC).
TL;DR: My suggestion is that you should take it to an expert to check it out if you don't have sufficient knowledge/experience to test it yourself.

 

[wingman99]

I shorted out mosfet with a DMM a long time ago and it killed the motherboard just like you described.

 

[cubusmedusa]

I have to think where to test it. Lets see. Now its time to go to bed.
At least I did not kill it during OCing.

PS: I think we can forget my other thread I opened 5 minutes before the crime happened

 

[EarthDog]

Update the thread so as not to have people reply for no reason.

I'm pretty sure that your motherboard and PSU are both dead. Take your DMM and measure the voltage between green and one of the black wires, it should be 5V.. If it's anything other than that, count it as dead. If it is 5V, jump the PSU (unplug EVERYTHING from the motherboard, connect the green and one of the adjacent black wires with a piece of metal, clipper would work best, don't worry about those harmless 5V). If it jump starts and you hear the fan then you need to measure all the voltages in the 24-pin connector according to this. The tolerance should be between +-5% and +-10%. If all the voltages are okay, then your PSU is fine. As for your CPU and motherboard, I think they're both dead. You need to test them with other components. I also had a problem with a cheap PSU which fried everything besides my graphics card so I just replaced it (it was a cheap replace anyway as it is an old but yet powerful PC).
TL;DR: My suggestion is that you should take it to an expert to check it out if you don't have sufficient knowledge/experience to test it yourself.

A bit late with this and some information is wrong... yikes (ATX spec is 5% dude).

PSU works...

 

[cubusmedusa]

@wingman
ok. **** happens.
Is there a reason why this middle pin is so easily accessible if not connected? Its really easy to touch it. I just slipped off the other pin for a moment.

Edit:
at least I learned that Vcore at mobo was 0.8V and 0.93 reported by CPUz

 

[Spreco]

A bit late with this and some information is wrong... yikes (ATX spec is 5% dude).

PSU works...

Is that the only incorrect information or is there more I should know about?

 

[cubusmedusa]

@Spreco
thanks for your explanation. I overlooked it before. messages came in pretty quickly and updating the page kind of let me overlook your post.

 

[cubusmedusa]

Is there a reason why this middle pin is so easily accessible if not connected? Its really easy to touch it. I just slipped off the other pin for a moment.
CPUz

any ideas?

 

[EarthDog]

Ask the mobo maker why... We didn't design or make em.

Edit: Spreco, just the 10% value. 5% is atx spec. Anything over that is outside of spec. I alluded to more.things but it was just bad.timing as hementioned psu jumped.