We have a carrier board that we solder the RCM3400 onto.
The boards are tested before soldering onto the board and then they are programmed once onboard.
Of the 16 units created, two will accept the new firmware, but do not run once firmware is uploaded. They will not run in debug mode from Dynamic C either.
Unfortunately, due to space constraints, the boards are soldered in and realistically, the only option for taking them off is to dremel the RCM boards in half to get access to the pins to properly desolder them.
We also replace the onboard oscillators with pressure tolerant variants from the carrier board.
I have checked that the clocks are received at the right pins and that they are the correct frequency.
I have checked power voltages and ground connections.
I have checked the voltage at SMOD1 (programming pin) though this shouldn't affect debug mode.
I have checked the votage at RSTIN (reset).
I am at a loss on what to check next and would like to find a problem that is common to both boards, in case it is systematic.
I would appreciate any help.