Well,
I finally got the Wave sorted out.

I've fixed the display and prior to installing it I've checked all the I/O and everything is OK again. So I'm looking at the display card and I've notice that some component pins were soldered pretty deep in the circuit board. I've installed it on the handle without electrical connections and look between. Some of the component (stabilizers) pins were almost touching the handle body! It could be that when I was installing the display for the first time I pushed it to hard on the cables behind so it short-circuited to the handle body.

I've clipped the excess pins, installed the display, key-on and the thing works to the day!

OK, that's enuff of this monologue for me.
I hope someone will have a good use of this info.

Regards!