Thick black lines (of toner down each side of printed page

try to replace magenta , Yellow , CYAN

I had this problem, I believe from overuse/heat.

I removed the toner, gave the roll a clean, then set a clean through the printer and it should disappoint.

The narrow pink line is coming from your magenta toner/drum cartridge. You may be able to open the from cover and look at the 4 toners. If you look at the magenta (like pink) cartridge, you might see the thin line on the drum surface.
The multicolored band that sometimes shows up on your prints is most likely the transfer belt unit. This is caused by an area of the belt that is not being cleaned very well. This probably tends to show up when you are running mutilple prints of a page.
So it looks like to may need to replace your magenta toner and look at getting a transfer belt unit.

Try cleaning the charge wire. Move the lime green plastic handle from one side of the image unit to the other in the groove. If this doesn't work you'll need a new image unit.$$$$$. note: Make sure green handle is moved completely to the right when finished or black line will occur.

Hello, Andrea.

Sounds like either your printer needs a new fuser assembly (If the teflon roller gets scratched or starts to disintegrate you will get lines or black marks on the page) or you need a replacement toner.

Hope this helps.

Easiest step to do would be replace your toner.
Next Step is 1/2 self test page. This means start a print job and after the paper is picked up open the toner cartridge door and cause a jam. The paper that you see after you remove the toner will show the current print. If the mark is seen on the paper there then it is the toner cart. If you dont see it on the paper then it is most likely your fuser causing the issue.

tthis is really old 25 years plus. replaced the drun cartridge which also contains the toner good luck canon sr tech

Seems like the drum needs changing. This is the most common cause for print problems in these printers. If using the high yield TN 6600 toner then you need to change the drum every 3-4 toners. If using the low yield TN 6300 toner then the drum will need replacing every 6-7 toners. Hope this helps

Shake the toner cartridge left to right, then try.

It must be the black pcu , the cleaning blade picks up dirt and causes these lines , it can also be the black developer giving you trouble , if you want be very carefull aand strip the pcu open you will see the lines only on the inside and not from outside , then you will know if it is developer or the cleaning blade