Have followed all instructions and was careful and I think everything is intact but on trying to charge am not getting anything. Will try leaving it plugged in to charge overnight as per someone's suggestion above. But if anyone has any other suggestions as to things to look out for / check if I can put right on reopening then these would be much appreciated!
Same for me for the 1.8mm screw.
Weirdly I had to use two different screw attachments to remove the pentalobe screws so possible they use different screw heads for each one sometimes.