One fundamental challenge to making repairs is evident even before inspection. A resistor or op amp replacement in the strain gauge amplifier circuit will require adjusting the amplifier offset. Which is no doubt a register in the microcontroller flash memory. Easy enough if you have the...
Just stumbled upon this as I typed 'Powertap disassembly' in to Google search. I have a few failed hubs with different failure manifestations from which I might build some frankenhubs. And/or check PCBs for cracked solder joints and re-solder.
That was a very nice sequence of assembly photos...