Nhokas

Hello. Digging in some old boxes, i found my Aiwa AM-F70 and some MD's. Connected it to the power outlet, just to confirm that the battery was dead, and it turned on. For 10/15 seconds the main screen showed no disc info and date and time. After that, the info vanished. The MD is working, the headphones display work 100%, but the main screen only lights up but has no info whatsoever.... Any idea how to solve this?