So how old are these units?
Do they display memory in the 5000-6000 range on startup? If so they are generation 1 TIMY from 2002-2003
The only solution with these is to send them back to ALGE to be repaired.
14 years is a pretty good run and these timers owe the owners nothing. Be prepared to take the printers off and buy new TIMY3 W and swap parts.