Suddenly toner started dumping onto the pages as they came out. lots of toner inside copier. a 12" by 1/3 inch screen was found inside the copier too.

If the toner cartridge is dumping toner it is defective and needs to be replaced.

Open the front of the printer, and you will see the four toner drums; cyan, magenta, yellow and black. Immediately to the left of the cyan drum there is an "L" shaped drawer : That's the waste toner drawer. It pulls straight out. If you enjoy driving around and spending money, you can buy a new one. If you are frugal and practical empty it as follows:
To do this cleanly I recommend wearing a pair of latex gloves! At the top of the container there is a square opening with gray foam on the inside edges - this is where the toner can be dumped out. Take an empty bread or bagel bag and put it over the end of the cartridge far enough to cover that square hole plus another inch. Gather the end of the bag and secure it with a rubber band or tape making sure the hole of the cartridge is INSIDE but not taped shut, and the bag's edges are properly sealed. Now you can turn the cartridge upside down and agitate it in different positions until all the toner is dumped into the bag. Flick the bag with your fingers to let the toner fall to the bottom, them put around the bag to keep all the toner at the bottom, and carefully remove the tape or elastic. Using a lightly moistened paper towel clean up the cartridge and reinsert it into the printer.

Now if you haven't left too much air in the bag gently take the end with all the toner in your palm, gather the rest of the bad with it into a small ball in your fist and pull your glove off over the whole lot. take that in your other hand and remove that glove.
Voila! The cleanest toner dumping ever!

Most toner dumping is caused by bad leaky cartridges. Remove the cartridge matching the color that is dumping and holding it over a piece of white paper, give it a tap. If you can see toner on the page then most likely that cartridge is shot and will need to be replaced.

The part that you are talking about is not from the fuser unit. It is from the drum unit, it is most likely the primary charge grid. It is part of the drum that charges the drum..... You may just want to replace the drum unit..... If the grid fell off the plastic holder may be broken... Good Luck

The chip in the toner is faulty, it tells it to dump all the toner. The provider of the toner should change the toner for you.

Hi ejazmusavi:
Try this.
Toner/developing cylinder 37.7 mm (1.48 inches)
Toner/primary charging roller 37.7 mm (1.48 inches)
Heating element 56.5 mm (2.22 inches)
Transfer roller 45.2 mm (1.78 inches)
Pressure roller 62.8 mm (2.47 inches)
Toner/drum 75.4 mm (2.97 inches)
Feed roller 55.1 mm (2.17 inches)

Hope this helps

Looks like the ridges inside the cartridge are catching. Here's a solution;

http://www.ahfx.net/weblog.php?article=133

the problem in your machine is on the drum unit there is a arching on the mc unit.located in the upper portion of the drum unit.if you have an old drum unit try to install it again just for testing.and check if ther is a dumping toner again.

We to have this issue with one of our 1600's. I tried to resolve this by replacing the fuser with a new one. Haven't got back around to trying to resolve this as it such a mess to get started. Someone resolve this issue yet?

When the paper is fresh out of the printer, does the ink that looks okay smudge if you rub it with your finger? If so, it means the fuser is going bad. Otherwise, it's probably a bad toner cartridge that's leaking toner onto the paper.