These "physical" questions are always the toughest.
I don't have an HP OfficeJet G655xi here to look at. Do you see screws?
The underside of the glass
should be sealed so that no dust can get into it.
On my HP OfficeJet 7130, the underside of the glass is sealed. There is one Torx screw head that looks like it might allow me to take the glass off. But really, there is no way for dust to get on the other side of the glass in the 7130.
The
manuals for the HP G55xi only include a Users Guide and a Quick Setup Poster. There is no hardware maintenance manual.
The real answer seems to be that ink is so expensive and printers are so cheap -- it almost makes sense to buy a new printer every time you run out of ink. :lol: