HP Envy 5055 is printing completely blank pages

This is really strange.

Try to reset the printer:

pull out power cable from printer and from the wall outlet.
Wait a minute and put in the adapter in the outlet, and then plug in power cord into the printer.

Turn on the printer.

I think you have to remove ethernet cable, if you have one

Probably won't help, but this is maybe the only thing you didn't try

Weird thought, test the print on colored paper, maybe the default Font color is set to white.

Berton said:

Weird thought, test the print on colored paper, maybe the default Font color is set to white.

Printers don't have white color.. (some exceptions)

Helmut said:

The problem is likely to be the electrical contacts and/or incorrectly inserted cartridges.
HP put a protective film on the contacts and when inserted is pushed out of the way.

Trying to clean them yourself tends to be counter productive, repeated insertions was much more successful when I had such an HP Printer.
The position of cartridges after insertion went to a marked position if either cartridge was inserted wrongly/dodgy contacts.

The printhead is on the cartridges, so you get a new one on each cartridge.

The worst case would be the printer dying for other reasons

Section 6 page 37 of the Manual seems to indicate a printhead, may need cleaning.
http://h10032.www1.hp.com/ctg/Manual/c05643392.pdf