PDS-E not working on Ryobi 524 GX

I was hoping somebody could shed some light on a problem we are having.

our CMOS battery has failed on the computer inside the PCS-H.
Around the same time our PDS-E would no longer scan the control strip or take spot readings.

I thought perhaps settings for COM ports or something similar had been stored in the bios and subsequently lost? The densitometer still illuminates when the button is pressed to take a reading but no longer seems to communicate with the computer

And tips would be massively appreciated