Avtech KPD startup question

[Hendee 0]

Hi

I got the system initializing hang on a KPD674ZB after a power down. The forum suggests a firmware restore. However when I follow the procedure (start up with pins 5 and 6 shorted, firmware in the usb drive), I get the correct screen - ie. "Enter USB upgrade mode ..... ....AppImg_4.bin...Loading 0% but it stays at 0%, so it never loads.

Does this mean that the flash chip is toast? I tried with a couple of different versions of the firmware. Or maybe the firmware is stored on the HDD - seems unlikely? If so, any way to confirm if the HDD is OK?

Thanks for any input.