Try the original DJI Assistant, that one was hackable: a simple change of parameters and you had full access to the developer console. It also featured the famous 'reset to factory defaults' button. A quick search online will throw up the...
DJI have already honoured their replacement policy with the original owner and the a/c serial has gone on their blacklist because that drone now belongs to them. I'm afraid you're stuck with a paperweight.
The battery management I/C (chip) on the RC1A and RC1B controllers main board is prone to failure, which is another reason why the older controllers can't hold a charge. Perhaps a good alternative would be to scout out a reconditioned RM500.