i have an older s300 canon printer i've never had a problem with till recently. when i print out a picture or anything else there are straight lines running all through the background. i've done all the nozzle cleaning, alignment and everything else possible in maintenance and am kind of stuck. all this printer does is print but its been dependable. please don't tell me to get another printer. i already realize i might have to but this is a shot in the dark for some help. manual hasn't helped much. don't even know if you deal with prionters in this forum.

I've got an old Cannon multipass C755 that I use for faxing only now. One of the things that helped it print when I used it for that was changing a setting.
Start>settings>control panel>printers>right click your printer and select properties>advanced. There is a setting for spooling or printing directly to the printer. If it's set to spool try changing it to print directly.
Check your ink also and you might even try the old soaking the heads in warm water trick, just the heads not the whole cartridge. Be very gentle with them, they can be damaged very easily. I can't remember if my Cannon had separate ink tanks or the cartridges but either way try to clean the heads in a small bowl of good warm water, let them soak awhile and then gently dry them and try to print again. Best of luck!
LG ;)

Are your print heads built into the cartridges [best arrangement because the heads are renewed with the cartridges], or into the printer [when the print heads are old the printer is finished]?

I use "Cartridge Flush" from www.jrinkjet.com [USA] or www.jrinkjet.co.uk [UK] to clean my heads. Let it soak with the heads submerged in it for a few hours.

clean the catridge with a damp cloth, if ur printer has a print head do remember to lean it as well, and also don't forget to clean the encoder strip as well, don't spare the encoder rod as well !! i havn't tried on canon printer, but it works for my HP printer !! :)