Logitech MX Master 3 repair, not charging

NutritioN · 16 Mar 2021 at 10:49

Hi,

I got one of these at an okay price second hand, knowing I could source a new battery if it was on its last legs.

It worked for a few weeks then didn't seem to hold charge or charge at all. So I got a new battery but that has the same issue. Is there such thing as the charging circuit going bust? Anything else I can try?

It feels like it stores a tiny bit of charge then dies. Even when plugged in, so the mouse doesn't work as a tethered mouse.

Plug in to charge = green light pulses
Turning on while plugged in = can pair (number flashes, and pairs)
Using while plugged in = seems to work for a few seconds then turns off.

Mint_Sauce · 24 Mar 2021 at 22:39

I would try plugging it in to a charging brick from a phone, see if that kicks it in to action.

NutritioN · 24 Mar 2021 at 22:54

I've tried all sorts! USB off a power strip, Google phone charger, turned off and plugged into desktop USB powered hub...

All seem to have the same impact.

Mint_Sauce · 29 Mar 2021 at 13:15

Sounds like it's kaput, I guess clutching at straws maybe attempt to re-flash the firmware. Not sure if it would be possible through Logitech Options or not. It does sounds like the battery or charging circuit from my very basic knowledge of this stuff. Maybe someone plugged in a charger that didn't regulate voltage etc and it's fried the charging circuit? If you take it apart and sniff the board, does it have that nasty burnt smell anywhere?

Could try brushing over the board as well as just unplugging and reconnecting any connectors to make sure everything is seated nicely? Guessing you've probs already done this if you've swapped the battery over but worth mentioning.

NutritioN · 29 Mar 2021 at 13:51

There was nothing visible that I could see, I didn't go as far as taking the whole PCB out. From where the USB power in goes, I think it might be worth looking underneath the PCB.

Thanks anyway.