Cleaning a Laserjet 4

[PetrolTed]

I've got crap coming out on the whitespace of my prints.

I wiped the rubber(?) roller thing in the printer yesterday.

What should I be cleaning? Is there a guide online anywhere (I don't have the manual).

[PetrolTed]

Thanks. It is repeating patterns so I guess it must be the roller. The cartridge is still churning out dark print so I didn't suspect that. That said it is about two years old now.

[PetrolTed]

Guess it's worth getting hold of another cartridge as this one is pretty ancient. It's been in the printer for two years and was sitting around before that.