I'm afraid I can't help you on specific repairs, although there might be more info if you rummage around the forum a bit. This particular tank has been mentioned from time to time and as far as I remember has a very high problem rating.

It could indeed be possible to buy, for example, a relatively inexpensive smoke and sound Heng Long tank and swap out the electronics, but it might make more sense to put the Abrams in the closet for another day and devote you attention to your new Heng Long instead.