So far I have installed the replacement screen as per the anycubic video.
Replaced the FEP.
Re levelled the build plate
Upgraded the firmware to the current level

I then set about running a test using an established print which I know works as it has been used multiple times before.
The print failed to attach to the build plate but also didn't attach to the FEP.

I then resliced the model using both the current version of Chitu and again using the current version of Photon Workshop and retested.   Both these failed identically to the original test.

Anyone got any ideas what I have done wrong/missed steps?

many thanks

Mossy