MCU bootloader dropped

[jack_huang1]

Dear:

       Using NXP S9S08DZ60F2MLH to design a BCM, the project has been mass produced. Product software using Bootloader+ applications. All functions of the product are normal when it leaves the factory, but all functions of the product are invalid after the customer uses it. After receiving the faulty prototype, perform the following tests: 1. The bootloader connection program fails to connect to the device; 2. 2. The running indicator light of the single chip is off; 3. The test crystal has no waveform output, and the test phenomenon is the same after replacement; 4. After the bootloader is rewritten, the connection is normal. After the application is upgraded, the product functions are restored. May I ask the possible cause of this problem? Thank you.

[vicentegomez]

Probably your code was corrupted maybe by EMI/ESD.

Maybe the device was turned off when it was writing to the flash this can cause damage.

I recommend that you try to reproduce the problem in your facility. With this, you can decide the improvement that you can implement on your design.

There are some application notes about EMI and ESD on the nxp web page that can be helpful 

Regards

Vicente

[vicentegomez]

Ok, I will check it, but also I will delete it, because this is on the public community

[vicentegomez]

 I check the part of the schematics and it looks ok

Please let me know if you have more information

have a good day.