Printer trouble.

I don't even know if it's worth it but I've been having a lot of trouble with my printer. It's been working pretty good for the past 3 years or so but I've tried a bunch of stuff and it's still messed up. It does stuff like print one page perfect and then the next 3 pages are a ll weird and streaky. I've replaced the cartridge 2 times and tried a bunch of other stuff but it still does it. It's an HP officejet 4215 all in one printer. Has anyone ever had a printer repaired? Where did you go? Is it worth it? Any suggestions would be helpful. Thanks.