Hmm. I don't know to be honest as the version I had was perfectly fine after the repairs I undertook. I took precaution of grounding myself before touching anything incase a current passes through and destroys a component. If he can start it and run a game otherwise, there won't be any damaged components. Its maybe somewhere with the voltages....
I'd check my battery first if I was you.
Then check by running the PDA without adding the bluetooth for a while. See if it runs OK as that with TomTom on but not with the aerial attached.
Thats all I can say at the moment I'm afraid
BTW do you charge it in the cig socket while in-car?