Ask Max: iMac screen lines - what can I do?
I'm wondering if Apple ever took responsibility for these irksome lines??
After my G5 iMac developed a bunch of these lines, they told me at the local Mac shop I'd have to replace the screen. After three months (and almost $600 later) the new screen was out of warranty and developing new lines, mainly on the right-hand side.
Now there are about 23 of them.
There was only one Repair Extension program for the G5 iMac that I know of and that covered the logic board and power supply. That program is over now but it would not have required the replacement of the LCD. You may be able to convince Apple that this is an unacceptable product lifespan for your iMac and would like them to consider other options, I just do not know how successful that will be. If the LCD work was done by an Apple Authorized service center you should have enough justification to a least start a conversation with Apple Support.
Sorry to hear about your problems and I hope it works out for you.