AnsweredAssumed Answered

STM32F407Z bootloader problem

Question asked by slobodnik.igor on Nov 25, 2012
Latest reply on Nov 26, 2012 by slobodnik.igor
We used STM32F103Z on one our boards, using the programming via UART1 with Flashloader Demo application. Everything was fine till the moment, when we decided to replace it with STM32F407. Of course the package is the same (144 pins TQFP), with all the reccomendations mentioned in AN2606 document were made (some stitching was made on board).
And the problem arised... Some boards are OK, but some failed to programm with message "Device not recognized". We use the last Flashloader Demo application, downloaded from ST website (Version  2.5.0). Even more - we replaced the CPU from the board been programmed to the board that failed, and tried to program it again - it failed. But, this programmed CPU succesfully communicates via UART1 with perepherials, i.e. UART1 on board itself works fine...
Unfortunately, this happened at our remote production site and I can not investigate the fail directly. Worse of all, that they sent me 2 boards that failed there, and I succesfully programmed them at my site. 
Would you please to suggest at least the direction of investigation?

Thank you in advance,