HP 110 "garbage" on screen

[dave-in-kc]

I picked a 110 (and a portable plus) up recently. I hooked both up to a 6v power supply and the 110 seems to "work" but the screen is garbled. I can navigate to the memo writer and the keyboard works but it alternates characters (pressing "rrrr" gets "2r2r"). I've taken the boards out and cleaned and reseated all cables and chips but no luck. The portable plus machine works fine. Any suggestions?