hi, just got a Redi-Line inverter from eBay ("DA12L-1600-A-1")i started removing the brush covers to do an initial inspection. when i took out one pair of carbon brushes i could see one was missing and the other was damaged. also noticed the commutator (or whatever it's called) is (badly?) worn and gouged. the one brush that was missing the steel spring was protruding from the brush holder and jammed in such a way that it touched and wore against the copper commutator. you can see the part of the other brush holder (white) behind the copper commutator, there are two brushes in each holder on both sides of the commutator. what i'm wondering and would like to ask here is do you think the wear (in the photo) would necessitate complete disassembly of the unit and take the armature into a electric motor shop to have the commutator turned/repaired/smoothed? is there a simple way to smooth it out while it's still in place that i can do at home without having to disassemble the unit and take it to a electric motor repairman? (i'd imagine it's knackered and being that rough will eat up any replacement brushes i'd ever put back in it.) (i assume it's probably impossible to tell from a photo how badly the commutator is damaged, i was hoping maybe there'd be like a "black and white" situation here, either "it's ok" or "you HAVE to get it smoothed out") thanks.
(i guess my second question would be how in the heck did the brush get out of it's holder in the first place!? the only thing i could think of is someone opened it up and didn't put it back together correctly, left the brush dangling out of it's holder when they reinserted the brush holder and it got whacked off and as it went flying off it hit the other brush too and damaged it.)