Hardware and Printers

[Mitchel]

I'm having a problem in printing in my printer, it is a Hp ojpro8600. It is printing but it is too dark and in one end of the paper it is in dark shade and i don't know what to do? I tried changing the cartridge and everything but it's not working can anybody say what is the problem in my printer? Is there any possibilities of my printer having any software Installation problem?