The ground fel off my battery and now u5 smokes when I give it power. This is a v3.0 board

best time so far 14.3 @ 101.1mph(no traction)
www.cnnmotorsports.com

Off the top of my head I would say no but the more i think about it, I would say its possible, the battery acts as a voltage filter in a way. If you read the tips on connecting for power and ground the install states to ground close to the battery to avoid noise in the MS. Take the ground away and now the alternator is supplying power straight to your assys.

Send Matt (extremers) an email to check this post, he wound def have a much more in depth answer.

Terry

Replied to your message Paul. But to me, it doesnt sound like your ground just simply came off, from what you had described. When you blow the main engine fusable link and the alt fuseable link, that means that there was a direct short on the positive wire to ground. U5 getting hot means that you have something in that circuit shorting directly to ground. Burned traces, shorted part, anything in that path. That sucks though, becuause 80% of the MS board is run off of the 5V regulator. I'd highly doubt its U5 directly, as it's a very robust part. I had gotten a defective PCB before, and there was a direct short to ground on the regulated 5V side of U5..it got super hot, and of course no 5v output either. It worked just fine once i got a new PCB though. HOpefully you can visually see what is shorted out on the PBC, but if not, then it may take some time to diagnose. De-soldering suspect parts and then seeing if it is still shorted to ground, is one way to diagnose. Use a multimeter set to continuity, and on the 5v side of U5 goes one meter probe, and then the other to ground. If you have a short, the meter will show no resistance, and continuity(dead short). Once you find the short, the meter will not react and/or show resistance. I have a meter that lets out a beep, so its easy to identify a short. I would first test the processor, which is the easiest, just by removing it from the socket, then see if U5 still gets hot/grounded.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

Thanks for the e-mail and reply.. Again I am not using the stock wireing /fuses. The regulator is form an older chrysler that had an external regulator unit. The car was running great I probably have over an hour of run time on the new motor with the squirt setup. It all happened when the battery fell off the ledge in the trunk and the ground fell off. I will do some trouble shooting tommrow when I have off. It might be easier to buy another squirt and try to fix this as a backup.

best time so far 14.3 @ 101.1mph(no traction)
www.cnnmotorsports.com

well the 5v is shorted to ground. I found a bad zener d12 but still have a short. Not havinf much luck finding it though...

best time so far 14.3 @ 101.1mph(no traction)
www.cnnmotorsports.com