I'll give you some hints from my years of experience as a copier tech (same technology). The cleaning paper trick may work but you are better to do this yourself. Most fusers are easily accessable after removing a couple of screws on the guide plates. You can also find instructions on the internet if you look as well eBay has repair manuals for just about everything out there.
The fuser is a basic heat and pressure unit. There are two rollers in a laser printer fuser - and upper teflon roller and a lower silicon roller. Sometimes there is a third roller or pad resting against the upper roller to clean it (cleaning roller) and the rest - halagon heating lamp (NEVER touch this with you fingers - oil from them will cause hot spots on the glass and cause premature failure) and of course the pressure springs. Most fusers are self cleaning with the help of a cleaning roller/pad (usually on higher end/high speed printers). If the rollers are dirty them something is wrong.
Dirty roller problem one - cheap generic toner. Sure you may have saved a few bucks but the toner has different values than the OEM toner and will start building up on the fuser rollers. Either you clean your rollers on a regular basis or buy better toner.
Dirty roller problem two - upper roller is dirty. See problem one or the cleaning roller (if applicable) needs to be replaced - or the teflon coating is worn. Clean a strip off the roller with a cotton rag and Isapropal (sp?) Alcohol - works better when fuser is hot (there other stronger chemicals you can use but they are highly dangerous to the health of you and the machine and unless you really know what you are doing - they should be avoided) Look at the roller after cleaning - is it dull? Is there major scratches, chips, missing coating? A good teflon roller will be shiny. Scratches and chips will show up right on every print made. If worn, it needs to be replaced.
Dirty roller problem three - lower roller dirty. See problem one or replace cleaning roller (if applicable). If you do a lot of double sided copies, even with good toner, this roller will become dirty (build up of toner). You may have to physically clean it once in a while. Look at the roller, the silicon should be soft and slightly shiny. If it's dull, hard, (dried out) and/or chipped - it should be replaced. A lower roller should last 3-4 times longer than the upper roller but heavy use, heavy paper, can shorten it's life.
Simon, thanks for your tip. I actually have a copy of Apple's Service Manual on the printer. After I read it, I dare not touch it! It is just way too complicated. One little screw up the whole printer will be unusuable. And since I only used up half of the page count, I rather not open it.
The problem I have is that the print on the right hand side (about an inch into the right margin) is a little lighter than the rest of the print. I have always used Apple Toner and it remains the same even after I replace with a new one.
That's why I wonder if those clean paper works.....without damaging the printer.
When I first got my printer (it was second hand), every print out was faded. I first thought it was a dirty fuser, but it turned out to be a dusty ?scanner/laser? assembly. I just wiped the dust off and voila! It was a lot of work though taking my printer apart.
That might be your problem, but it also might be as simple as an undistributed toner cartridge. Try rolling your cartridge back and forth and from side to side to make sure the toner is evenly distributed within.