I bunged up my MPGuino >.<

[Oval_Overload]

I was all set to make a video about how to install the 'Guino in a Taurus. Then mine started acting funny. It would repeatedly reboot, then it started freezing, and then it completely quit working (while I was showing it off to my geek friends, no less). I discovered the solder connections on the yellow capacitor and the tan ceramic capacitor (between the USB and ATMega chips) were bad. I fixed the connections, but the MPGuino still does absolutely nothing when plugged in. System Profiler does, however, recognize when the MPGunio is plugged into my Macintosh.

Did I fry my ATMega? Could I have toasted the tan ceramic capacitor when re-soldering?

Any help is appreciated.

[myplasticegg]

similar problem but all of the joints look good... It was VERY warm when it was acting up.
Grateful for any help, Shane

[dcb]

spiffed doesn't check in here much AFAICT, you might ping him at the address in this thread if you are having problems with the kit:
http://ecomodder.com/forum/showthrea...html#post88735

[Oval_Overload]

Plastic egg, sounds like you have a short somewhere.

I re-flashed the MPGunio code to the chip, and the thing worked fine for 2 days, then crashed again. The Arduino program gives an error message whenever i try to re-flash the program. I built a second MPGunio, and it has done the exact same thing. *sigh*

[dcb]

You are using solid power from the battery and not ignition power?

[Oval_Overload]

I took a power tap off the fuse box after I verified it's always-on status with a multimeter. I might have to make a more resilient connection.

[Spiffed]

Originally Posted by myplasticegg

It was VERY warm when it was acting up.

It would help to know what was warm.

• If the regulator is getting warm, you've got a short to ground somewhere.
• If the ATmega168 is getting warm, you've got current running through the rail clamp diode arrays.
  • Check that none of the inputs drop below ground and add a diode if they do!
  • Check that the two Zener diodes are soldered correctly and in the correct orientation
  • measure the input at each terminal and look for voltages above 5.1v or below ground

[Spiffed]

Originally Posted by Oval_Overload

Did I fry my ATmega? Could I have toasted the tan ceramic capacitor when re-soldering?

The yellow 'lytics are particularly prone to damage, this usually results in a short to ground. Since the FT232 detects correctly, we know the ground plane is OK.

The ceramic cap between the FT232 and the ATmega is the 3.3v output from the FT232. The USB section plain won't work if it's damaged in a bad way.

Have you tried uploading new firmware to the chip using the arduino software?