yea it could be a thousand things, you could try replacing the battery and if it didn't work then I would just sell it as a non working unit and maybe some one might pick it up to see if they can get it to work or use for parts.

people like that are out there. I mean hell I bought a non working famicom from overseas just to see if I could figure out a better way for the A/V mod so who knows.

p.s.
not much luck on that but there has atleast been some progress