Ko pds 2343 help....!!!

[hf integrale]

Hi guys..I've got a few ko pds 2343 fet servos(love them)
But recently the one in my 2wd has started to make a lot of crackling
Sounds when in use...and when stationary now...I've had the top of and all gears are intact..can it be fixed or is it knackerd?if it can who is best to use?
I have the ics USB adapter and software if that can be used on these servos.
Any help much appreciated
Cheers Justin