It didn’t take long to figure out that a dead X axis and an message saying “TMC CONNECTION ERROR” meant that one of the stepper drivers on the SKR E3 Mini 3D printer control board had released the magic smoke. Manufacturer BigTreeTech replaced the board under warranty, and the printer was back up and running in short order. But instead of tossing it in the trash, [Simon] wondered how hard it would be to repair the dead board.
The short answer is, not very hard. There was no question as to which of the four TMC2209 drivers was shot, since the X motor was the only one experiencing a problem. The drivers unfortunately aren’t socketed on this board, but after a little kiss with the hot air, the old chip was off.
[Simon] didn’t have any spare TMC2209 chips, but the TMC2208 has the same pinout and is a drop-in replacement. The TMC2208 is rated for a bit less current, but it shouldn’t be a problem under normal circumstances.
Other than the stepper connector getting a little toasty during the installation, the swap went off without a hitch and the board was up and running again. [Simon] ended up putting the now repaired SKR E3 Mini in his Ender 3; a nice 32-bit upgrade compared to the ATmega1284 that was originally running the show. Though in the past, he’s managed to squeeze a bit more performance out of the older 8-bit board as well.