Troubleshooting BK7231 Easy Flasher Errors on Treatlife Dimmer Switch with CB3S

Hello,

I am trying to flash a treatlife single pole dimmer switch with the BK7231 Easy flasher. The board has a CB3S as seen in the attached tear down pictures. I have flashed many of these, but recently have been getting two errors during flashing. It seems to switch between the two following errors:


Starting flash new (no backup)!
Now is: Friday, October 4, 2024 9:37:24 AM.
Flasher mode: BK7231N
Going to open port: COM3.
Serial port open!
Getting bus... (now, please do reboot by CEN or by power off/on)
Getting bus success!
Going to set baud rate setting (115200)!
failed with serial.BytesToRead 0 (expected 12)
The beginning of buffer in UART contains data.
Failed to set baud rate!



Starting flash new (no backup)!
Now is: Friday, October 4, 2024 9:16:58 AM.
Flasher mode: BK7231N
Going to open port: COM3.
Serial port open!
Getting bus... (now, please do reboot by CEN or by power off/on)
Getting bus success!
Going to set baud rate setting (115200)!
Will try to read device flash MID (for unprotect N):
failed with serial.BytesToRead 0 (expected 15)
The beginning of buffer in UART contains data.
Failed to read device MID!
Going to read encryption key...
failed with serial.BytesToRead 0 (expected 15)
The beginning of buffer in UART contains data.
failed with serial.BytesToRead 0 (expected 15)
The beginning of buffer in UART contains data.
failed with serial.BytesToRead 0 (expected 15)
The beginning of buffer in UART contains data.
failed with serial.BytesToRead 0 (expected 15)
The beginning of buffer in UART contains data.
...
The beginning of buffer in UART contains data.
Encryption key read done!
Encryption key: 00000000 00000000 00000000 00000000


I have tried various uart USB converters, and used both Linux and Windows successfully in the past, but not with these two most recent ones .

Any help with troubleshooting would be greatly appreciated.

Thank you.

were your most recent successes the same blue PCB variation and with same TuyaMCU on the reverse side?

>>21250394 yes they were.

Hmm, weird. Usually TuyaMCU gets in the way of flashing so needs to be removed from the equation somehow- either by cutting a trace, putting the MCU into reset mode or by desoldering the Beken module. Not a different USB-TTL this time is it?