Vertical thick lines/streaks

[rameesvazhatt]

Vertical thick lines/streaks on right side of every print on my m651 

[Valsimot]

Transfer belt, you can try to clean it.

Replacing it with the new one will fix print quality.

[AlS77]

It can be an issue with the toner cartridges, but typically it's a result of the ETB (Electrostatic Transfer Belt) that no longer cleans the belt of waste toner correctly. There is a cleaning blade at the narrow end of the belt that cleans any leftover toner from the belt into a small tray and a wire auger attempts to carry it into the waste cartridge. If you use non-HP toner cartridges, it will tend to clog up and cause problems as the toner is not made well to flow smoothly. You can, very carefully, remove the black top cover at that end and carefully empty out and clean the toner from in there and from the blade, but it usually doesn't last long before it becomes a problem again. You also don't want to clean the rubber/silicone blade too much as it has some lubrication powder on it that helps it slide along the belt. Just use a small piece of paper to slide along the edge that touches the belt to loosen and remove any toner that may be stuck under it, then dump it out. The toner cartridges have some lubricant powder mixed in to help keep it lubricated. I usually replace the belt and tell my customers to use HP toners instead of any 3rd party toners to maintain the function longer.

[Repairatrooper]

HP now uses an actual anger instead of the spring. They have also changed the waste bin and it is very easy to break the lock tabs on the new ones. It could be a piece of paper stuck under the wiper blade. I would remove the belt and look closely for any foreign material. Do not touch the belt surface with your bare hands as this will cause print defects from the oils on your skin.