We are using free-scale controller MC12334 in our application, initially few baords we manually assembled and tested . it was working fine.
But as a first of mass production we assembled 200 board we used Pick plcae .but after the assembly majority of boards are failing to program the controller.
When we trying JTAG it showing "Write error" when we contacted with assebly house they says they have prepacked with 120 degree for 7 hours(Controller and Bare PCB).
Reflow temperature profile also same as recommended by freeescale.
Can you please answer few my doubts
1) Write error meaning controller internal flash corrupted or it can be JTAG contact issue with JTAG connector?
2) Prebaking 7 hours at 120 degree is recommended?