Hi mob, unfortunately you are joining many of us with this problem. If you have Applecare bring it in immediately. I'm assuming you have a 17" white iMac 2006 with a serial number beginning W8. If so please read the link. It should answer all your questions. Good luck.
Same single vertical line here, and my ser # begins with W8.
What the heck is happening to the Apple brand? It was superior to p.c.s, now sites, screens, are crap!
Line Fixed!
My iMac got a line last week. I took it to the Genious Bar here in San Francisco, and it was fixed in 10 days. Free, because I still am under 3 year Apple Plan. Absolutely no problems w/ staff.
I think some of the info in these Forums is "alarmist", so be careful w/ anything you read.
Not sure what you mean by "fortunate" it isn't like the option to buy an AppleCare extended warranty isn't available to anyone buying a new Mac, unless you mean "fortunate" because your extended warranty may have expired.