Well...
Just think logic way.
The power supply is the CCont. -> If there are power failures, maybe the power supply has problems, NOT THE AUDIO RFI(cobba)!!! don't bother, if it doesn't have audio or signal faults.
The other problematic chip is the "chaps", this is the charging controller. If damaged, phone turns of or doesn't even turn on.
If none of these help, Try to rehot the flash and the ram, and upload new SW and EEprom, and do the Mbus jobs.
Good luck :P
regards
Bscorp
[email protected]