When I tried to play a game, push the sensorfields, it registers some moves, but after a while the device does not respond anymore. A problem I already observed with a 2nd hand & shipped Alto and I finally decided to remove the Eproms for potential reselling as the problem lies with the sensorboard and/or connectivity with the printed circuit board.

I did find a descriptiion on how to open the device (after I discovered the same) :
http://www.chesscomputeruk.com/html/...tellation.html