One common problem with the laserjet 4200, 4300, 4250, and 4350 series printers is the way the fuser is seated, or not seated in the printer. It's possible to run the printer with the fuser not completely locked into place which can cause wearing on the gears in the fuser, wearing of the black gear in the swing plate assembly, and broken blue fuser tabs. It can also cause the paper to feed into the fuser not at a completely perpendicular angle to the upper and lower fuser rollers, potentially leading to a ripped fixing film. Whatever the cause, if your swing plate assembly needs to be replaced you will usually hear a grinding or thumping noise coming from the back of the printer. Usually you will only need to replace the black gear in the assembly, not the entire assembly. Replacing the gear is a fairly simple task, but does require a little patience. Replacing the entire assembly is a huge job and potentially frustrating job that we won't discuss here.
Getting access to the black gear:
First, turn your printer off and unplug it. Facing
the back of the printer, you need to remove the hinged back cover. Press inward on each hinge tab to release the tabs and free the back cover.
Press upwards on the blue levers located on each side of the fuser and simulatenously pull the fuser towards you to remove the fuser.
Remove the formatter cover panel by grasping the panel firmly and sliding it free towards the back of the printer.
Remove the screws circled below left, which hold the formatter in place. Then remove the formatter by sliding the formatter towards the back of the printer, as shown below right.
CONTINUED . . .
