Chosen Solution
I have a iMac Intel 20" EMC 2210 Early 2008 Core 2 Duo processor. I replaced the hard drive in the unit and everything seems to be fine, except I can see some VERY faint broad black and white vertical bands. I can’t say that they were there before, because the unit was passed to me without a hard drive and therefore I couldn’t really check it out. Could the HD replacement disturbed a screen connection and would possibly re-seating them help?
See if an external display shows the same symptoms. Sadly, it maybe the LCD that got damaged somewhere along the line.
Mine are caused by my cigarette smoking . So every two years or so I take the display glass out and clean it and it’s like new.
