Well that was easy considering I've not even handled a PCP before let alone worked on one.
Looking at diagrams convinced it was blockage some where between fill valve(?) and gauge/regulator. Stripped everything carefully in step sequence with cylinder attached to give a controlled squirt of air at each stage and found this. No not the pin Assume it entered via the quick fill port maybe. To recap symptoms were no reading on gauge and no discharge of air on firing. Back together and working well in my inexperienced opinion.
Oh and though got no suggestions removing the spin cap regulator is so easy!:thumb:
Thanks for looking