Certainly sounds like a power suppy board problem, could be anything on that board, but from your description could well be just the failure of the 'start up' capacitor. If that is the problem I'm suprised you cannot find an 'old fashioned electronics engineer' who could diagnose and replace this inexpensive component, or any other failed capacitors.
Alternatively as mentioned by hazfiend a search of eBay might find a working PSU board.