Burnt 20 pin ATX socket

[ThePCGuy]

I know I've read of people having problems with burning the plug on the motherboard and powersupply. I've been doing a bit of researching and it seems that every case I've seen is the same. The 5V lines on the plug are the ones to burn. I've been wondering as of late, what devices in a computer are being run from the 5V line anymore? What would cause such a draw that you would burn the socket? I just received a Epox 8rda+ from a forum member that has been declared dead. It too is suffering from the burnt atx plug (which I've already removed). There does not appear to be any visible traces that have been burnt also, simply a blackened plug with remenants of the powersupply that was used previously. I've heard people mention that it could be a contact issue inside the plug on the 5V lines. That is hard for me to believe, that all four 5V lines have bad connections. Finally, we've got bad capacitors. Could bad capacitors (failing GSC caps that were standard on all previous epox boards) allow for a dead short thus drawing max amps from the powersupply and in turn frying the 5V line? I have every intention of fixing this board (already replaced 11 capacitors, 2 more left). I've scoped out a 20 pin socket on Mouser that looks (after talking with a tech there) like a replacement for the original. Has anyone had this same issue and found the reason for it? Thanks.

examples:
http://www.goeaston.net/~bowsertb/pics/Burned-ATX.JPG - This one is very minor compared to what I'm mentioning.
http://pages.sbcglobal.net/ender026/Temp/Img_1181s.jpg - This is more like it.
http://thepcguy.myvnc.com/jim/atx.jpg - Here we go.

- Jim

[shellshock]

It usually is caused by the connector not being plugged in solid, and it archs. Mine did the same thing, and I could not figure out why my video card was artifacting. Finally found the cause

http://i2.photobucket.com/albums/y47/shellshock-gw/Burntatxpins.jpg

[nvidiaOCmaster]

Owned?

[ThePCGuy]

Shellshock, I would completely agree with you had the connector had one burnt pin. However all 4 of the 5V lines were burnt like in the photos.

- Jim

[four4875]

well, i would think that if one of the connectors was kinda loose fitting, all of them in the plug would be about the same. then as the current gets drawing, they heat, and oxidise and all start conducting worse, and all get hotter and it escelates itself from there.

is the nb and sb's power regulated from the 5V line? what about cpu? ive always wanted to make an atx extension cable where i can hook in an ammeter to see how much current mobos are drawing, but have never got around to it lol.

my old gigabyte mobo with a socket A cpu (i cant even remember what i had that long ago) with an A power psu got toasty andburnt its socket a little nad the plug, they got hot and were brown, and insanely brittle. i didnt think that system was drawing all that much powr, no insane clocks or anything.

[ThePCGuy]

Thanks for your response four. Again, I'd totally agree that if one of the pins was getting loose, that all of them might suffer from the same deal. The problem I've got is that it's only the 5V lines. If you lookup "burnt atx" on the web, you'll find many instances of the same problem. And every one of them is burned on the 5V line.

- Jim

[L337 M33P]

Two of my Asus boards, A7V333 and A7N8X have decidedly brown-looking ATX plugs. This is due to the CPU getting its power from the 5V line and not 12V, resulting in a higher current draw. A loose crimp or two would result in dramatic heating of the connectors...

This is one of the reasons for moving to 12V for most high-power supplies.

[t12121]

I also had this happen but much worse. The plug was melted on those plugs (5 volt) I think. Lucky for me I had a buddy willing to work on it and fix it for me for just parts (no labor) I am currently using it still today. It was from a loose connector I believe

[ThePCGuy]

Well I just got all 3 boards that I've had in line soldered up and ready to go. I had two 8kha+ with 24 bad capacitors total (all GSC 2200uF 10V caps, typical), and this 8rda+ with a couple of caps and most importantly the atx socket. I was able to located a female atx 20 pin plug that suprisingly worked, I picked it up from mouser.com. Part number is: 538-39-29-9202, listed as a 20 CKT VERT HEADER. I'll test it in a few hours to let everyone know how she faired.

- Jim