Danny DiAmico wrote:



The ground straps seem to have good contact, so, I think it's
the MMU or the CCU but I don't know yet what to do next.
http://u33i.imgup.net/groundstraebd1.gif
Since the CCU is powered up and communicating with the buttons and
indicators, it is likely OK. Since there was a big POP, and the CCU can't
communicate with the MCU, which is where all the big power circuitry is, it
seems REALLY likely something in the MCU popped. When you get it out, I
think you are likely to find visible damage.

Jon

On Tue, 26 Apr 2016 14:56:09 -0500, Jon Elson wrote:

Since the CCU is powered up and communicating with the buttons and
indicators, it is likely OK. Since there was a big POP, and the CCU can't
communicate with the MCU, which is where all the big power circuitry is, it
seems REALLY likely something in the MCU popped. When you get it out, I
think you are likely to find visible damage.

Thank you for that advice.

I'm kind of stuck like a deer in the headlights at this point because
I have to diagnose if it's the CCU or the MCU (or the power rectifier).

I'm kind of at a loss for diagnostic procedures because the diagnostic
test described in the manual didn't kick in.

Danny DiAmico wrote:

On Tue, 26 Apr 2016 14:56:09 -0500, Jon Elson wrote:

Since the CCU is powered up and communicating with the buttons and
indicators, it is likely OK. Since there was a big POP, and the CCU
can't communicate with the MCU, which is where all the big power
circuitry is, it
seems REALLY likely something in the MCU popped. When you get it out, I
think you are likely to find visible damage.

Thank you for that advice.

I'm kind of stuck like a deer in the headlights at this point because
I have to diagnose if it's the CCU or the MCU (or the power rectifier).

I'm kind of at a loss for diagnostic procedures because the diagnostic
test described in the manual didn't kick in.
Just pull the MCU and examine it closely. If you can't find anything
burned, then it gets harder. But, if there was a loud POP, I think you WILL
find visible damage. It is possible that there is a fuse on that board, and
the failure of the fuse under hard short conditions made the noise. So, Ohm
out any fuses you find.

Jon