Dark color lines across page

[Lititz4]

I have a Color Laserjet CP3505x, which shows thick colored lines on the printout. I have sent the print a couple o time to a HP shop for calibration. It does solve the problem but problem comes back after just a few hundred pages printed. I need to fix it, but do not want to sent it to repair shop anylonger. I feel it does not help once it comes back and always has a funny explanation. I love the machine when it works fine, it is kind old, but has served me well. I just want to learn how to solve the problem once for all.

[ALS-77]

Can't see your picture yet, sometimes it takes a bit before it's viewable. If the lines are about 1/2 inch thick across the page, the problem I've seen on other printer models, are due to non-OEM toner cartridges. They just seem to wig-out from time-to-time. Very intermittent. I simply replace all the toner cartridges (usually with OEM's) and it's fixed. Never know which cartridge or cartridges are the problem because it's too intermittent to troubleshoot properly. Replacing with non-OEM cartridges was always a gamble, sometimes they worked and other times the problem came back. This probably explains the funny explanations from the repair shop, because they don't know what is causing it, but it stopped long enough to send it back to you.

[Lititz4]

Thank you for your reply and sorry for picture issue. In reality lines are not across page, They start on left margin, for maybe a couple of inches, discontinue for an inch or so and start again for a couple of inches. This repeats across the page. It is odd because it normally starts only  with black, and after printing a few pages the other colors starts the same way. Blacks are more to the left side of the pages, colored are more to the right of the page. I do use non OM cartridge. This is an american purchased printer and in my country HP do not sell that cartrige so i by them from other suppliers.

https://photos.google.com/photo/AF1QipN2qr8Nna9o9oTAdoGpaPYYgqj0_mkRXrdl3JnB 

[Repairatrooper]

You definitely have an issue with both your cyan and yellow cartridges. Almost like the cartridge was not assembled correctly and the drum unit is not level.

[ALS-77]

I'm finally able to see your picture. That is a very odd problem. They're all very similar in design, just different colors and positions on the page. I've never seen anything like that before. It could be a static or high-voltage kind of internal buildup/discharge or anomaly that affects all the colors at the same time which would explain the staggered colors going down the page as they are spaced one above the other in the printer at about the spacing shown. Try doing a stop-test where you stop the printer by opening the front door with the paper directly in front of the toner cartridges and you'll see what I mean, or you could use the paper with the images to match it up to the toner cartridges inside to see how they line up. I suspect a bad ground connection somewhere. Could be a bad wiring connector, missing ground screw or grounding spring, etc... Finding that though could be near impossible. It could also be a bad ETB (Electrostatic Transfer Belt) as it uses high-voltage too.