Purple flash on the motherboard when I turned on PC

[boks]

I built my pc 2 months ago, my liquid cooler died a month ago and its replacement came today. I installed it in and turned on PC when i suddenly saw a purple flash on the right side of motherboard near ATX power supply, home's fuse tripped and whole power went down. I haven't tried turning pc on again.

Red circle is where flash happened : https://imgur.com/a/tEe32dK

 

Here's my specs 

• CPU: Intel 8600k

• Mobo: MSI Z370 A-PRO

• Corsair H115i aio

• Ram: G-Skill 16GB 3000MHz

• SSD: Samsung 860 evo 500GB

• GPU: Galax 1070ti ex

• PSU: Corsair Rm550x

• Case: NZXT S340 elite

What should I do now?

[Cbfbrolol]

Sounds like fault on motherboard. Look for burn marks or cracked capacitors.

[boks]

6 hours ago, Cbfbrolol said:

Sounds like fault on motherboard. Look for burn marks or cracked capacitors.

I can't find any burn marks on the motherboard or on the atx power pins though I just noticed there's some thermal paste near atx power at area of shock, you can see it in the pic as well. my thermal paste is noctua nt-h1 and it says non electrically conductive.

[Cbfbrolol]

That paste is non conductive so should not cause a short circuit although it sounds like that is what has happened. Try turning the motherboard on after clearing away the paste and making sure the area is dry. The only way you will ever really know.

[boks]

6 hours ago, Cbfbrolol said:

That paste is non conductive so should not cause a short circuit although it sounds like that is what has happened. Try turning the motherboard on after clearing away the paste and making sure the area is dry. The only way you will ever really know.

Thanks for the advice! I'll see how it goes.

[nick name]

It sounds like you saw some arcing. On those cables are there any exposed metal? Perhaps it wasn't the board and was the cable that caused it. 

[boks]

10 minutes ago, nick name said:

It sounds like you saw some arcing. On those cables are there any exposed metal? Perhaps it wasn't the board and was the cable that caused it. 

It was arcing. I can't find any exposed metal on the cables, can't find any gaps on wire insulation either. The arcing looked like 6 cm vertical line between the second ram and 24 pin power.

[ProximaOfZeal]

4 minutes ago, boks said:

It was arcing. I can't find any exposed metal on the cables, can't find any gaps on wire insulation either. The arcing looked like 6 cm vertical line between the second ram and 24 pin power.

Whoa, that wouldn't happen even with serious electrostatic buildup. 6cm arc would be lots and lots of kilovolts, the only way I could imagine that happen it would be a thunder hitting your power line. It'd help if you could make some close-up photos of the area from different angles.

I mean, it'd help to try and determine the cause, if there was something arcing then it's most likely cold dead.

[boks]

 

21 minutes ago, ProximaOfZeal said:

Whoa, that wouldn't happen even with serious electrostatic buildup. 6cm arc would be lots and lots of kilovolts, the only way I could imagine that happen it would be a thunder hitting your power line. It'd help if you could make some close-up photos of the area from different angles.

I mean, it'd help to try and determine the cause, if there was something arcing then it's most likely cold dead.

In the fifth picture first arc was small (orange line), then the big arc happened (red line) from same origin as first one. The fuse tripped right after that. Also do you think my cpu/gpu/ram are fried as well? I could only test the hard disk and its working fine.

[Cbfbrolol]

An arc that huge is ridiculous. Idk how that could even happen. Almost certain if that is the case any circuits that was charged by this arc will be dead.

[Cbfbrolol]

The charge needed to create an arc as previously mentioned is huge. An arc is basically air being turned to plasma from the massive ammount of current being forced through it. To achieve an arc so big, with such a low voltage peice of equipment would be quite a chalenge. Are you sure as mentioned earlier lightning didnt hit a power line, which im sure would of damaged other things in your house.

[boks]

1 minute ago, Cbfbrolol said:

The charge needed to create an arc as previously mentioned is huge. An arc is basically air being turned to plasma from the massive ammount of current being forced through it. To achieve an arc so big, with such a low voltage price of equipment would be quite a chalenge. Are you sure as mentioned earlier lightning didnt hit a power line, which im sure would of damaged other things in your house.

I am pretty sure there was no lightning at the time.

[Cbfbrolol]

What type of switch went off on switchboard? A RCD or a over current detector?

[boks]

5 minutes ago, Cbfbrolol said:

What type of switch went off on switchboard? A RCD or a over current detector?

Its a MCB with 16 Ampere capacity, I don't know much other than that.

[asand1]

What you probably saw was a trace glow and burn out like a light bulb fillament, not an actual arc. 12v at 10a will do that when there's a short to ground.

 

Did the old cooler leak on the Mobo?

[boks]

33 minutes ago, asand1 said:

What you probably saw was a trace glow and burn out like a light bulb fillament, not an actual arc. 12v at 10a will do that when there's a short to ground.

 

Did the old cooler leak on the Mobo?

I am pretty sure the cooler didn't leak, only its pump died though today I found out electrical wiring in my house is screwed up, neutral and ground wire were in contact with each other somewhere in the home circuit, Also, there were 2 dead geckos inside power outlet my pc was connected to.

[Stefan Payne]

On 17.7.2018 at 7:36 PM, boks said:

 

In the fifth picture first arc was small (orange line), then the big arc happened (red line) from same origin as first one. The fuse tripped right after that. Also do you think my cpu/gpu/ram are fried as well? I could only test the hard disk and its working fine.

 

 

 

 

 

Oh dear...

What did you do?

 

The ATX Connector isn't really inside the socket. The gap between the Connector and Socket must NOT be there. So you haven't really inserted it all the way...

 

So pls remove it and look at the connector, post photos. It might be possible that it is destroyed due to arcing...

[boks]

On 7/19/2018 at 5:23 PM, Stefan Payne said:

Oh dear...

What did you do?

 

The ATX Connector isn't really inside the socket. The gap between the Connector and Socket must NOT be there. So you haven't really inserted it all the way...

 

So pls remove it and look at the connector, post photos. It might be possible that it is destroyed due to arcing...

I had removed the atx power to inspect the pins, I reinserted them loosely to take the photos. Unfortunately I don't remember if it was loose during original short.

Here are the pictures, I can't see any damage on them.  So far I have tested running only the mobo with psu and mobo lights, case fans turned on.

 

 

[boks]

Update: I replaced the motherboard just to be safe, tested my pc with new motherboard. It booted up first try, not a single component was damaged. Even the RAM next to the arc is working fine, ran memtest on it for 10 hours with 0 errors. So, I am guessing it was a short to ground after all. Thanks for the help everyone!

 

 

 

There's small usb issue on the new mobo but I'll sort it out.