the screen shows displays all modes ok
used till with keys and manual i have turned off power
pressed cash key and power on to obtain all modes till
roll reads initial clear ok -still no keyboard action

dave barrett, October 2010

If you have done an initial clear, then it sounds like a hardware fault if the keyboard doesn't respond at all.

If you need a service manual for repairs, c-tech has one here:

http://the-checkout-tech.com/manuals/cashregisters/Samsung_ER-650_service_manual.html

Registerman, October 2010