A washing machine is trapped in a fault state even though all the components function (AFAICT). The controller board has two ports:
- ISP (to attach an ISP programmer to flash new software)
- USART (4-pin serial port: 0v, TX, RX, 5v)
I’m guessing the ISP port is useless without whatever proprietary software is needed. But what can the USART do for me? Can that be used to obtain the error code and clear it, or reset the board to the factory state? Has anyone done that, without documentation?
You might see if you can find a service manual for the specific make and model, it could be as simple as a hidden breaker switch that flips to factory defaults.
Of course not all makes and models are out there, but a lot are!
https://www.servicemanuals.net/en/washing-machine-service-manuals
There is no service manual within my reach. I would have to resort to bribery, torture, breaking and entry, and theft to get one. Thanks for the link but that only seems to cover N.American makes.
This is in fact why I am looking to probe the serial port. To try to poke around since I don’t know the secret steps to reseting the board.