How do I get rid of vertical streaks?

Check the remaining service life of the drums, also check the condition of your transfer belt. It is most likely your problem is one of those two elements.

Are the streaks horisontal or vertical on the page?
What printer? Laser or InkJet?
If laser, and streaks are vertical, you might have some dirt stuck in teh tomer cartradge or somewhere along the paper path
If laser, and streraks are horisontal, your toner cartridge might be dirty or leaking toner

Open up the document feeder and clean the scanner glass. If the streak is larger than 1/4 " wide, you have a bad scanner block.

Don't know about your "primed" toner, but go to Diagnostics and run the PQ test. See what that looks likes. Go to Disable Cartridge Check and swap the black and cyan toner. Run another PQ test. Are the lines still there and are they black or cyan? If they are cyan, the cartridge is bad. If they are black it's not the cartridge. It going to take a tech to look at it.

Remove all of your toners and clean them off. Replace each one and make sure they are well setted in the unit before going to the next one. Make sure the carosel turns smoothly and nothing is hanging up on the sides. Reboot the whole printer and let it settle for 5 mins before printing. toners come lose sometimes when you turn carosel around. Hope this helps you these printers are a ***** to deal with ,but when they are right there great.

There is a glass strip, take out the drum, inside on the front side it's about 6" x 1/2" just wipe with cotton and alcohol

I was going crazy! Had a tech come in and look at the machine - needless to say he did NOTHING! A friend came over and was trying different things. It was that the "rack" that the toner cartridges sit in was not fully seated - once he pushed down a little and heard it "click" I had no more black streaks. AMAZING

Try a new Cyan toner cartridge. If nogo, will need a new transfer roller or transfer belt (I used to work on these printers but forgot if they use a belt or not... I will check on the DCSE site and post back)

Depending on the type and model of your printer this could be several things mostly related to the cartridge or drum if you have a separate toner/drum system.. Since you have stated you have shaken the toner, I am assuming you have a laser printer. New belt, has me confused. Green thing leads me to think you are talking about the drum. If so, did you purchase a new toner cartridge or new drum cartridge?

Several components inside the toner or drum cartridge will cause vertical streaks. It depends on where these streaks are occurring and how wide the streaks are. We call these repetitive defects and they can be measured to determine which part is at fault.

Also, if this is a multi-unit machine (print/copy/fax/scan) Check the platen glass or ADf feed unit for white out. That has been a major culprit of vertical streaks on the page.

More specifics about the model of machine and cartridges being used would be helpful in trying to solve this problem for you.

I've refilled the toner cartridges a few times now and never had a problem with vertical streaks until recently. I refilled both the cyan and magenta and when I ran the test page I had dark vertical streaks on both sides. I fiddled around cleaning things, running cleaning paper through, changing reset resistors but to no avail so eventually decided to buy a replacement refurbished cyan cartridge since the streaks looked mainly blue and bingo... well almost now I just have very light magenta streaks. The issue is obvious when I compared the old and new cartridge, the replacement toner is a much duller cyan and is of the wrong consistency since once it's been in the printer everything gets covered in it which is why I think it causes the banding to occur. I'm just trying to work out now whether to try refilling the magenta again (v. messy) or just go for another refurbished cartridge (£34).