M2-ATX Burt out IC

djmickyg · 04-08-2008, 09:59 PM

Hi,
My M2-ATX wasnt working, the PC would switch on and off when ever it felt like it.
I've noticed ive got a burn out IC, could someone tell me what is ment to be written on the IC so i can change it? I havent had a real good look at the whole board yet as it's still in the car, I will pull it out when i get a chance.

I have circled it in the attached picture.

Thanks

djmickyg · 04-19-2008, 01:27 AM

hey is a pic of the burn IC..
can some one tell me what's written on it??

chromatid · 04-25-2008, 08:54 AM

That burned surface-mount component is really a transistor (N-channel FET), even though its package looks like an IC (notice the silkscreened label Q4 rather than U4).

It's identical to Q3, on the other side of coil L1 in the square gray can.

Full markings:

F (Fairchild logo) AG1AN
FDS
6680A

Datasheet at http://www.fairchildsemi.com/ds/FD/FDS6680A.pdf

Since it's really just a 3-terminal device (top 4 pins tied together as Drain, 3 of 4 on the bottom as Source), if you locate a matching FET in some other case, like a TO-220 it should be possible to bend the pins and fit it in.

Of course, there might be something else wrong that caused that FET to blow in the first place... it's part of the +12V buck/boost regulator circuit, if that's any clue.

Good luck!