As Peccavi told: You need to replace the CMOS battery.
It's a button style battery. Usualy, it's about the size of a nickle or a quarter.
Electro, August 2013
Internal main logic pcb has a battery that keeps setup and time/date, as battery ( 2013 type ) starts to go flat the date / time is the 1st to go after sometime the setup will be having problems
Roger, August 2013
Very probably needs a new CMOS battery.
A tiny watch style battery inside - to remember the date 7 time while the power is switched off.
