Chainsaw Repair

@pleasant

Stihl tech says = There is no drive gear. Stihl battery tools are direct drive brushless motors. Can be lots of things...I just had an msa90 trimmer come through that the housing was rubbing the motor just enough to cause it to bind and done exact same thing...the whine is typical to a brushless stalling.
Noone outside of a dealer is going to get it fixed because of the techline support needed.... There is no real service manual, most of the diagnostic info is internal memos and experience.