Why did this happen ( scorched connector )

snowdog

snowdog

snowdog

Soldato
Joined
27 Oct 2005
Posts
13,804
Location
Netherlands
Hello,

I was slowly having some odd issues with my PC, about half a year ago it stopped going out of standby ( wouldn't post when coming out of standby sometimes, then never). Recently, the pc stopped cold booting properly, it would turn off as if it short circuited after 0.5-1 second of being on ( or sometimes be in a loop of turning on for half a second then off), but not always and it would usually boot the 3rd or 4th time I unplugged the power and retried.

So I started keeping my pc on 24/7, after a week or 2 it started randomly turning off and being harder and harder to boot.

I checked the BIOS, and the +12V line was just 11.2v, I know the mobo measurement isn't always accurate but I remember it being 11.97 when I bought it), keeping an eye on the 12V line while my pc was on showed the 12 V line being anyhwere between 11.2 and 11.45 during a working Pc ( used AIDA64 to check it).

So I started suspecing the PSU, I have a Corsair with 5 yr warranty so I asked at work if someone had a spare PSU, and got a Be Quiet 550W to borrow.

The PC doesn't even show a (5VSB) light with the power plugged in and I cannot boot ( with the be quiet I got from a colleague). I checked the connector and saw this ( on my own PSU and board):
2014_12_03_17_12_24.jpg

2014_12_03_17_12_52s.jpg


It STILL sometimes posts on my own PSU, I haven't tested the be quiet on another pc yet, as it looks like a dud PSU ( should at least show the mobo light), but what the hell happend to my own PSU ?
It's a Corsair TX850, which is more than enough to run a i7 940-12gb-gtx570-7hdd's/1ssd, 6 usb devices & 6 fans. Everything was plugged in fine, the 8 pin cpu connector looks normal, the gpu had it's own 8+6 pin power, etc...

What happened and how do I prevent this ?
 
Last edited:
Those are the 3.3v pins, which would indicate a problem with either PCI cards or your motherboard itself. Not sure what modern PCs even use the 3.3v line for apart from PCI cards. The only thing I can think of is that there was a huge draw on that line, mega amps means mega resistance, which means mega heat. Would've needed to be a lot for that to do that though, so I'd say something that shouldn't be earthed got earthed maybe?
 
Zefan said:
Those are the 3.3v pins, which would indicate a problem with either PCI cards or your motherboard itself. Not sure what modern PCs even use the 3.3v line for apart from PCI cards. The only thing I can think of is that there was a huge draw on that line, mega amps means mega resistance, which means mega heat. Would've needed to be a lot for that to do that though, so I'd say something that shouldn't be earthed got earthed maybe?
Click to expand...

Yellow = 12V.

I'll be filling out an RMA form at Corsair soon, but still stumped as to how this happened in the first place.
 
Last edited:
I wouldn't have thought it was the PSU at fault, unless you mean the connectors in the plug were not connecting correctly.

For the connector to get hot and scorch like that there was too much current passing for the connection.
So either there was not good enough connection between pin and socket causing it to over heat or some thing on the motherboard is pulling too much current over loading the connection
 
I think the 12V voltage dropped to low on various occasions.

Less voltage = more amps needed to pull the same wattage.
And for those 2 pins it was simply to much.

I think anyhow.
 
snowdog said:
I think the 12V voltage dropped to low on various occasions.

Less voltage = more amps needed to pull the same wattage.
And for those 2 pins it was simply to much.

I think anyhow.
Click to expand...

Wattage is power ie work done.
Lower voltage wont make it draw more amps, think of a light bulb, lower the voltage it gets dimmer, it doesn't stay the same brightness but take more current.

The voltage drop could be down to bad connection. The bad connection causes a resistance, you lose voltage across said resistance. With voltage and resistance you will use current and the only way the power is used is heat. ( bad connection gets hot)

or the voltage drop is from pushing the psu to its limit because the something on the board is pulling too much current.
 
The plug was fully in though, so whose fault is the bad connection ? ( just asking out of curiosity, in case corsair starts asking me the questions).

It's been well over a year since I touched the connector in the first place. This is not something that happened in a short time period, this has been going on for months if not years.

or the voltage drop is from pushing the psu to its limit because the something on the board is pulling too much current.
Click to expand...
All 4 fan ports on the board itself are used (fans and water pump).
Aside from that, I have the Gtx570 and an Asus U3A6 card on the pci-e 4x slot.

Not sure what else pulls 12V from those pins. Cpu has its own 8 pin plug. and GPU has had its own 6+8 pin power too,
 
Last edited:
Sometimes when ya plug a connector into the board if the metal clips havent gripped the inside of the plastic clip properly it pushes the metal connector out of hte back at little, and the loose connection could have been arcing.
 
momo56 said:
Same thing happened to me with a rampage 3 and a xfx psu. Had to pay £10 for a new cable. Xfx blamed it on the motherboard but the psu stopped working a year and a bit later.

http://forums.overclockers.co.uk/showthread.php?t=18451730
Click to expand...

Ha, I see I even replied to your post back then :D.

Either way my psu is giving low voltages, so I'm RMA-ing it for that as the main reason.

Mick-1965 said:
I notice a screw missing in the corner. Its not worked its way down the back of the board has it ?
Click to expand...
Nah, I started disassemling the pc as thought it was the board, mobo atm has 2 screws left.

BluD said:
Sometimes when ya plug a connector into the board if the metal clips havent gripped the inside of the plastic clip properly it pushes the metal connector out of hte back at little, and the loose connection could have been arcing.
Click to expand...
Meh, if thats what happened then why have I spent 100+ on a psu in the first place.
 
Thought I'd post an update:

Got a corsair RM850 replacement within 3 days after posting my old one to Corsair.

Since the new PSU, my pc works like old again, never have boot problems, and standby works again ( it didn't work any more, it'd either randomly come out of it for the past half a year, or simply not post anymore after coming out of it ( had to turn pc off then on, then it restored the hibernation, as I've got it setup as hybrid sleep.)).

Been using the pc for 4 days now, basic usage, watching series, and gaming. It looks like my mainboard works as intended and isn't damaged!
 
Result! I wonder how this affects your mobo resale value and whether corsair might have done a little more than just replace the psu?
 
Last edited:
Momo56 thanks for posting that, i have an XFX 550W Pro right now.

Will be getting a new PSU as soon as i'm able to.

Snowdog, kinda surprised that it didn't damage anything else as well. Looks like you were lucky :)
 
You must log in or register to reply here.
Back
Top Bottom