First: Replacement parts are not as easy to find for display's vs. computers. So this makes things from the beginning more difficult.
Second: Fnding replacement parts for Apple displays makes things even more difficult (simply because there are fewer of them around).
Third: Pretty much the only place you're going to find a replacement part (at a reasonable price) for a 2003 Apple Cinema Display is e-Bay.
There may possibly be some websites selling parts...but for a 2003 Apple display...it's going to be difficult. I know a few great websites that sell parts for older Mac computers...but they don't sell parts for displays.
What I mean by reasonable prices is...I know one website where a PRAM battery for a Mac computers sells for $3.99...and at a different website the same exact battery costs $28.00!!! YIKES!
I e-mailed them about it...and I think that they reduced the price to $23.00...still insane!
Good luck,
- Nick
p.s. Also remember...unless you are TOTALLY in love with this 22" Apple Display...the price you pay for a replacement part may cost close to (or more) than just buying a newer (still used) and much more modern display.
