[Ti] Loss of AC power

[Loren Schooley]

I am diagnosing a Ti 550 that won't power up any longer since the battery
has been exhausted. When I plug in the power cord the AC plug light does not
illuminate amber or green or anything. I put a volt meter on the power
supply and it read about 3.1v. 

Could it be the power supply unit, or the board? It does work with a
battery. Perhaps there is a AC power reset for protection somewhere inside?

THanKs!