Does using a non-HP or refilled ink cartridge void the warranty on the HP Envy Photo 7800?
Using a non-HP or refilled cartridge does not void the printer's warranty or any HP support contract. However, if printer failure or damage is found to be caused by a non-HP, refilled, or expired ink cartridge, HP will charge standard time and materials fees to service the printer for that specific issue.
From the official HP Envy Photo 7800 All-in-One Printer manual, page 3
Have a follow-up question?
Answers from the official manual.
Common questions