We have a weird problem on 2 HP Laserjet IIP printers. If you run a continuous print-test (Hold down Alt + Test for 5 seconds), the first page comes out very faint. But each successive page gets darker and darker until about the 10th page is almost perfect.
It's strange because we've had several of these printers for many years and now 2 of them are doing the same thing.
I tested their cartridges on a good printer, and the cartridges are fine, so the cartridge is not the problem.
Does anyone have any ideas of what the problem is? We're trying to get some idea of the cost of repairing these things, and whether it's worthwile.