socket 4 board toastred, repairable?

Sad day for me. I powered up my Socket 4 machine and was greeted with a terrible sound and smoke. I've kind of written the board off but seeing as its socket 4 and not easy to come by these days does anyone think it's savable? damage seems to be limited to these toasted things.

If it's just one of the capacitors that went kablooie, it's probably repairable. Get a toothbrush and some alcohol, clean the area up and then let's see another photo, okay?

Tantalums.... gotta love 'em.

heres a few more images. its pretty hard to get into that spot between the 2 PCI slots to scrub. you can see its that middle cap that went.



and from the back

I think it's worth repairing. Of course, if there's damage to traces on the inner layers, the board is toast.

The only worry I would have is if it got hot enough to ruin the plated-through hole. That second photo is telling; you can clearly see enough heat happened to reflow the solder on the end away from the slot.

Do you have a temperature-controlled desolder station? I wouldn't try this with solder wick or a cheap solder sucker, as those multilayer plated-through holes are fragile, and you don't know which layer the end of that cap towards the PCI slot is connected to. Gut feel is it connects to the internal ground plane, which would be good, but that's just a gut feel. The fact that the solder on the end towards the slot didn't reflow is good, and it would confirm a relatively large thermal mass, like a ground plane, is on that side. That will make desoldering a bit more difficult, though, as that ground plane will sink desolder heat just as well as it did the fault current heat.

Tantalums have a nasty habit of failing short-circuited, and significant damage to traces and/or regulators and other parts can occur when they fail.

If you decide to replace this one I would recommend shotgun replacement of all of that type on the whole board, as it is just a matter of time before another one goes pyro on you.

unfortunately my soldering skills are less then sub par and the soldering equipment I have is the most basic. seeing as you guys think there is at least a possibility its fixable I'm probably going to see if I can send it to someone more skilled at this point and hope it can be fixed.

If these are plain old decoupling caps, try clipping them out see if the board still comes up and salutes. If not, then prospects are probably pretty dim.

Chuck(G) said:

If these are plain old decoupling caps, try clipping them out see if the board still comes up and salutes. If not, then prospects are probably pretty dim.

Click to expand...

alright, good news. I hooked the board up and powered on and it actually posts. goes through ram count. I can access BIOS ok....so it looks like its alive. it displayed with both a ISA and a PCI video card. I'm guessing though I'll run into issues sooner or later with those caps gone.

Good. Decoupling caps exist to smooth out higher-frequency components of switching currents present on the various supply rails. Since PC traces act as inductors, you have to distribute decoupling caps throughout the supply rails, all the way to the small 0.1 and 0.01 microfarad caps that should be as close as possible to each individual IC's voltage supply and group pins. The effect of missing decoupling caps will be decreased stability under heavy load of the PC. Whether it will affect you or not is a toss-up.

Looking at the traces, if the PCI slot closest to the blown cap (the slot in the center of the second photo) is unpopulated, I suspect there will be no issues.