Well,don't think there is a battery backup, RAM board will hold parameters, agree try' jumping pressure sw. Sad to say its a Schindler, you never know. Unv means unavailable. Did you do a reboot? Press button on the board that is mounted to the Main relay board 3times in 1sec. Intervals,then when screen shows system boot, press and hold for 5 sec. This will reboot entire system. Sometimes you have to put controller on MR inspection. This clears most errors.