streaks

Okay, so this may seem a silly question and I apologise in advance, but I'm lost at this point... My printer is printing beautifully - for most colours - however some come out with a horizontal smudge/ fade about an inch from the bottom. (Photo attached). I've tried everything I can possible...

Hello everyone, I am new to these forums but I am glad they exist! I acquired an old Hp Color Laserjet 4500n and I just have to say, it's an awesome machine! I replaced drum,fuser, all toner, and I have a new transfer belt on the way, I have managed to get it to print black and white just...