Hello britishaudio,
Thanks for the update. I am sorry the partial reset didn't help any.
I would suggest calling Technical Support at this point to see if you are still under warranty, as they might be able to replace your printer. If you are out of warranty, then they would be able to give you all your different OOW options.
I don't believe another reset would help in this case, we have done all that is possible to troubleshoot the printer.
If you wish to call HP, this is the contact info:
If you are calling within North America, the number is 1-800-474-6836 and for all other regions: click here.
Regards,