Pronto charged overnight as usual, came down to find it "on" with a totally non-responsive screen.
Reset pin made no difference, I opened it up to find the batteries had leaked very slightly, cleaned it all up with isopropyl alcohol but no different.
I then swapped the display & touch screen with our other (good and working) one and proved them to be OK, the other screen & display connected to the "faulty" one also did not work.
The PCB connector where the touch screen plugs in looked a bit dirty so I cleaned that up and the screen now beeps when touched.
I then updated the firmware to fully reset it but it fails on step 4 of the screen calibration

Any ideas or help appreciated
thanks