The newer 03/04 models can cause issues.

If you notice toner spray inside the machine, then the drums and/or dev seals are worn. The develope does last past life, drums not so much.

Sadly the drums are massively expensive, if you can, buy in some 04 drums; these are cheaper but have a slightly shorter life. They will fit in both 03 and 04 models.

If you have ever worked on an 02, then the fuser is pretty much the same to disassemble.