Sorry ste i'am not clued up on these ion's, how's about replacing the RPK batteries and the backup battery and take it from there.
You have to start troubleshooting somewhere why not start with the batteries, if you don't have the correct test equipment,then I would think batteries first.
Just a suggestion mate, as I say i'am not sure!,,
Hope the guys can sort it for you, good luck.
e manno
September 2012