I purchased a Brother model HL-1450 because it seemed like a great deal, laser printing with 8mb of memory and PostScript emulation, which I needed.
	After having it for only a few months it began smearing and streaking toner all over the background of all the pages it printed.
	This printer is used in my house and has only printed a few hundred pages in it's lifetime, far fewer than should be expected without problems regardless of age of unit.
	I have tried numerous times to clean all the parts of the printer, taking care not to touch the drum itself and using lots of canned air to remove any stray toner.
	Replacing the toner cartridge seemed to help, but only temporarily.

I initially purchased a Brother because it was the brand being used at my work. Shortly after my purchase the two printers at my work began exhibiting the same issues, which were not permanently resolved by replacing toner cartridges or drums. They ended up switching to HP laser printers and have not had problems since, though it's only been a few months.

	After having an HP DeskJet 880C for a couple of years it began printing colors with lighter streaks on them. I've had a laser printer for most print jobs so the HP was not used much, probably under 200 pages. Very few full page or photo prints.
	I assumed that my non-use had let the cartridge become clogged with dried ink.
	I ran the  'clean' option from the printer's properties.
	The test page printed out, but the 'clean' did not solve the streaking problem.
	I proceeded to the 'prime' option, thinking that doing this would get the ink flowing smoothly again.
	This time the page printed out, but without ANY yellow printing.
	I assumed that since I had not regularly used the printer that the cartridges had just 'gone bad' from non-use.

	I purchased both color and black replacement cartridges to essentially make my printer as new again.
	I installed both cartridges and did the 'align' function.
	Upon printing a test page I noticed a slight streaking again.
	No problem, I'll just use the 'clean' function.
	After cleaning, the test page prints out with the streaking still there:

	So, I try the 'prime' function again, maybe the cartridge has been on the shelf a while.
	Nope! Now I have the SAME problem I got with my first cartridge, NOTHING YELLOW PRINTS!

	Now I'm fairly confident the problem is not in the cartridge but rather in the printer or the driver software since both my cartridges lost the ability to print yellow after the 'prime' function was done. Regardless, I have an unusable printer with two new cartridges.
	After looking online I found the procedure to get the printer to print an internal  self test page:

	Notice the yellow is still missing, so I'm ruling out the drivers as a source of the problem. That leaves either two bad cartridges that both mysteriously quit printing yellow after running the 'prime' function (unlikely) or I have a bad printer. Perhaps priming is doing some sort of damage to the cartridge. I'm not buying another cartridge to find out.
	Also notice the grid pattern is messed up on both the black and the color areas. Something is wrong with these two new cartridges.