been given a challenge on fixing a fried transmitter

[nivlacf1]

Ok so ive been given a spektrum dx3s that had a lipo conversion, the guy that had it connected the battery the wrong way round and blew it,(reverse polarity) ive been looking into if its fixable or not and what might of got damaged, has anyone ever repaired one of these, know of someone who has, or a link to a guide? i can not seem to find anything other than it could need the capacitors replacing, any other ideas would be greatly appreciated thanks