How do I know if I killed the board?

[peakbagger66]

OK, the title sounds obvious, but if the board still does not work after recapping, how do I know if I damaged one of the tubes or foils while desoldering as opposed to it being another issue preventing the board from posting? I've just removed the old caps, but I used what may be questionable technique with the solder sucker and a needle. Foolish, I know, I know...
Thanks!

[arneson]

Re: How do I know if I killed the board?

Check your resoldering very carefully on each cap.
A good light and a jeweler's loop gives a magnefied view of those connections that are closely ringed by ground plane.

[willawake]

Re: How do I know if I killed the board?

did the board still post just before the recapping?

[peakbagger66]

Re: How do I know if I killed the board?

No - the board didn't post at all. I haven't capped the board yet. I was just checking to see if there was a way to visually inspect the holes to determine if there was any damage. I'll get the caps soldered in today and we'll see...

[willawake]

Re: How do I know if I killed the board?

measure vcore. be careful it is not a cpu killer. anyway there is possiblilty of more work than recapping - fet/vrm chip damage. tell us how it goes.

[peakbagger66]

Re: How do I know if I killed the board?

measure vcore. be careful it is not a cpu killer. anyway there is possiblilty of more work than recapping - fet/vrm chip damage. tell us how it goes.

Oh I forgot, I did test against a known good power supply. I am pretty sure it was the caps - when I was desoldering them, one of the big ones started "sizzling" and when I pulled it off there were some liquid droplets...definitely some leakage happening. oy...that would suck if I killed a perfectly good board...

[willawake]

Re: How do I know if I killed the board?

when I was desoldering them, one of the big ones started "sizzling"

that can happen even with crappy caps that are new. not recommended to re-use caps removed like that. sounds like you had some good heat there anyway.

you probably didnt damage the board. but what i am saying that it may still not post because of damage when the caps failed. in case it does not post dont start trying to do the recapping again, just post your results and we will assist you with the troubleshooting.

[peakbagger66]

Re: How do I know if I killed the board?

OK, so I've soldered the caps in, the board (a shuttle FV25) still does what it was doing before - not posting.

When I plug the power connector to the back, there is a green led that lights up on the motherboard, near the memory slots. No clue what it is for. I hit the power button, the cpu fan twitches, and then nothing.

Any ideas?

[kc8adu]

Re: How do I know if I killed the board?

OK, so I've soldered the caps in, the board (a shuttle FV25) still does what it was doing before - not posting.

When I plug the power connector to the back, there is a green led that lights up on the motherboard, near the memory slots. No clue what it is for. I hit the power button, the cpu fan twitches, and then nothing.

Any ideas?

shorted vrm fet.
psu hits oc limit instantly on power up.
look for shorted mosfets.

[peakbagger66]

Re: How do I know if I killed the board?

shorted vrm fet.
psu hits oc limit instantly on power up.
look for shorted mosfets.

Oh drat. What's a MOSFET?

Black rectangle with three prong things sticking out of it? I think I am at my limit here...any pointers as to where I should touch the needle? I can post a pic of the mobo...although I wonder if I should let dead horses stay dead...

[Chris1992]

Re: How do I know if I killed the board?

yeah, the MOSFET is as you described. Why does willawake's sig say 'Merry Christmas, you wanker'?

[kc8adu]

Re: How do I know if I killed the board?

Oh drat. What's a MOSFET?

Black rectangle with three prong things sticking out of it? I think I am at my limit here...any pointers as to where I should touch the needle? I can post a pic of the mobo...although I wonder if I should let dead horses stay dead...

if you really need to save the board it may be best to send it in.
fet is a black square smt soldered to the board .
has two pins at one end.
think of them as switches.
if they stick on(short) the psu is connected across the inductor permanently.
psu shuts down from overload.
to further complicate things the pwm chip often gets killed too.