Help needed: Cortex board shortcuted with enclosure + trigger extension

dimduj

I've finally dress the LXR with the new  metal enclosure from Erica synth and build the trigger expansion but got a big issue:

The ribbon cable from the trigger expansion is really short and  has compressed the 2*6 header of the cortex board and shortcuts the 3v3 and gnd pin together when I closed the enclosure

Bad luck... 

Since then, the sequencer does not start anymore.

Everything else seems OK: I can activate/desactivate steps for each vocies. Each pressed button is responsive and the associated light  shine when I press the button.

Navigate between each page/voices/display. Even make an upgrade of the bootloader...

But when I press the start button.... I don't see the current step running over the 16 leds... (an there is no audio output.)

Here is a video of the issue: 

I thought the mainboard was fried thus I ordered a new mainboard few days ago. 

But the replacement of the main board don't change the behaviour ...

Okay ... So I change every IC like the HC4050, the 595 and the 165 (evrything except the atmega and the 6n138)

But still no luck...

Maybe an UART issue between mainboard and avr ? (UART fried by the shortcut ?)

I can try with an atmega 644PA (don't have a 644 version right now.)

But I don't know where to find the bootloader and the correct flags to burn it (assuming normal and PA version have different flags).

If someone could provide me the bootloader URL and the flags to burn it I could exclude the AVR from the suspect list.

Any help/clue would be appreciated.