Recently had a problem with a GTISO 520 engine starter. The starter motor internally broken, LAME hadn't seen that before. Ended up replacing not only the starter but also the starter adapter. COST $AUD 9,000 on exchange, but cheaper than a bulk strip.
As a side note the LAME, to get us home, hand propped this 435HP engine. I thought he was mad until he explained as a geared engine a small turn equated to a large turn internally.
Even after 40 years flying you learn something new every time you fly.