Hello all - I posted the original question and have to say I did not find a way to get it working. In the end the customer wanted the watch back and listed it on ebay as faulty with one of the new screens / digitizers fitted, meaning it looked nice but didn't work. I like the sound of the thought that the chip is not programmed on the replacements, I wonder if it's possible to transfer the chip over.. I'll have a look at the digitizer I bought and see if the chip can be transplanted. and update you.