M1-ATX toasted

**gothate** · 05-11-2005, 10:41 PM

First I'd like to say, good ******* timing on moving the boards. Bah.

Next, I seem to have fried my M1-ATX and I'm not quite sure how. I hooked everything up for the first time tonight, tried turning the PC on and the light went on and the USB hub went on but nothing else did. So I pulled everything out again, carted it inside and hooked it up the the ATX. Everything works. Pulling out the ATX molexes I noticed that the yellow wire had popped out of the M1. Aha, I said, that's the 12v rail! So I push it back in, hook everything back up to the car and turn the car on. I push the power button and smoke and fire shoot out of the M1. The chip located to the immediate left of the 8 pin white thing toasted. Looks like D7.
M1-ATX_big.jpg

Can anyone tell me what that is or why it burst into flame? The fuse on the damn thing is fine.

**rando** · 05-12-2005, 01:55 AM

The fuse only protects against pulling more than 10A at the input. That's 120W+ ... more than enough to create fireworks if something goes wrong internally or something gets shorted out.

I believe the part you're talking about is Q2 (8 pins). It's FDS9435A. It appears to be used as the load switch for one of the power rails.

It might help us to understand what happened if you can show us a picture of your supply. Also, which yellow wire did you find loose and where did you "plug it back in?" My assumption here is that you somehow either shorted or crossed two of the supply rails. This caused an excess current to flow through the Q7 switch and release the magic blue smoke.

**gothate** · 05-12-2005, 08:46 AM

This camera sucks, but you can see the toasted chip and the wire that was out previously. I just stuck it in the hole next to the red wire, it seemed to push in snugly.

**acura cl** · 05-12-2005, 10:40 AM

o shizz! that sucks..

**rando** · 05-12-2005, 10:49 AM

Yah, you put that wire into the correct hole. The 12V rail on the M1 is only rated for 2A. If you grossly exceeded that limit, damage like you have could occur. I don't know if the M1 is supposed to be overload or short circuit protected on all rails.

What were you trying to power? Also, could there be a short on your 12V rail somewhere?

Either way, I'm sure iTuner/mini-box would like to hear your story to understand what happened and why.

**sxt173** · 05-12-2005, 03:06 PM

Had the exact same issue with mine! Same chip (I think D7) got fried. In my case, I believe it is because I had the M1 mounted on a metal surface and the little metal pins on the bottom might have shorted - because I was dumb and did not remeber to put a piece of plastic between the mounting surface and the pins

I wonder if they can repair this!

**rando** · 05-12-2005, 07:31 PM

Originally Posted by sxt173

Same chip (I think D7) got fried.

It's Q2 but just looks like D7 in the picture because the tail of the Q and bottom of 2 are obscured by the chip.

I wonder if they can repair this!

They probably can. You might be able to also. That part is <$1 at Mouser. Swap it out and see if it works.

**Gredd** · 05-12-2005, 08:19 PM

Im a member of the club! Did fry the same chip when shorting the 12v rail by reversing polarity on cables to my screen. Stupid thing to do! Well I bought a new one but maybe its just replacing this chip to have a spare PSU! I can spare a dollar on that

So...you will need a pretty small tip on the solder iron. Any one done this repair?

**rando** · 05-12-2005, 08:32 PM

You can do it with a big tip and a solder sucker. Search google for instructions on SMT soldering. Flux is your friend!

**gothate** · 05-16-2005, 06:42 PM

Well, besides the motherboard fans and whatever else it normally powers, I had my Xenarc hooked up to it as well. I suppose it's very possible I had the polarity reversed, maybe that did it. I checked out some SMT soldering stuff...and I dunno about that! It looks like the damage is isolated to that one chip, but it's *small*! Maybe your idea of a big tip is way smaller than the soldering thing that I have...? Looks like you'd need something the size of a needle!