A local contract PCB manufacturer has asked me to look into whether a recent patch of STM32L151RET6 chips he has soldered onto customer’s boards could be faulty/bad/fake. I’m not very familiar with these devices (yet) or the operation of the boards they are used on.
The newer chip on the left is not working as expected (ending with 1.3). If the chip is replaced with one of the older batch chips (on the right, ending with 1.1) the boards work as expected.
The programming sequence seems to work the same for both devices (although verify comes up with an error for both, perhaps the memory is locked or something).
The boards do operate to a certain degree even with the newer batch chips, flashing LEDs and generating some beep tones, so the chips do have some operation. We are still trying to get some more information from the original designer of the board, but he no longer works with that company so may be difficult.
Has anyone experienced similar problems with these STM32L151RET6 chips. Is there known fake or faulty devices on the market or something. Or is there some difference with the 1.1 / 1.3 that could be the cause?
One thing I thought was a bit strange, the barcode on the original packaging from the supplier has been blanked out.
Thanks in advance if anyone can shed some light on what the problem may be or where to investigate further. I will try and find what the 1.1 and 1.3. signifies.