MJWSD05MMC stops responding immediately after power on

[martini1992]

I have a MJWSD05MMC with the same board revision as in your notes, it was working fine then started to lose signal, so I changed the battery and it was no better. I flashed v4.7 fw and then the device stopped updating the display, the same happens when removing/reinserting the battery (time and temp readings stay at their first value after turning on.

I have tried flashing v46 v47 and v48 using the instructions here https://github.com/pvvx/ATC_MiThermometer?tab=readme-ov-file#the-usb-com-adapter-writes-the-firmware-in-explorer-web-version and the behaviour seems to be the same.

I tried updating one of my spare LYWSD03MMC (needed to reset the BT PIN anyway) to confirm the instructions worked (and I was doing it right) and it worked successfully.

Have you seen this behaviour with MJWSD05MMC before? Any tips on fixing it? Maybe flash original firmware?