Posts: 451
Threads: 107
Joined: Nov 2005
There is a fault that produces this behaviour.
I'm sorry but I don't recall what it is. As I understand it (and I may be wrong) but the timer for the 10 minute power off is located on the display board.
Maybe you have a fault on this?
The problem may be a bad connection in the calculator somewhere. If you're feeling brave you could open it up and try to find and fix it.
The points of weakness seem to be the connections between the upper and lower board, and the connections to the display board.
Best of luck