I just want to thank everyone in this post, especially Mike and Willi for all the knowledge and effort. Here's mine and Willi's fix worked perfectly.
Mine is a 24 inch Apple Cinema Display. It was completely dark, although the fan was spinning, Megasafe was charging, USB worked, and the MacBook Pro's monitor briefly turned on and off while the Apple Cinema display flickered very briefly. I followed the service manual and found that very very dimmed image can be seen on the Apple Cinema when shining a flash light to it, this is a confirmation that the back light wasn't functioning properly. After getting a reading of 24v when testing TP81 in relation to the chassis ground, I decided to go with Willi's fix and gave it a shot (note that I'm not an electrician nor electrical engineer). And it worked, although the soldering was very difficult for me. As Willi said, remove R0444, 0445, and 0459, connect the three pull down resistors to the 3.3v (L0631?).
I just want to thank everyone in this post, especially Mike and Willi for all the knowledge and effort. Here's mine and Willi's fix worked perfectly.
Mine is a 24 inch Apple Cinema Display. It was completely dark, although the fan was spinning, Megasafe was charging, USB worked, and the MacBook Pro's monitor briefly turned on and off while the Apple Cinema display flickered very briefly. I followed the service manual and found that very very dimmed image can be seen on the Apple Cinema when shining a flash light to it, this is a confirmation that the back light wasn't functioning properly. After getting a reading of 24v when testing TP81 in relation to the chassis ground, I decided to go with Willi's fix and gave it a shot (note that I'm not an electrician nor electrical engineer). And it worked, although the soldering was very difficult for me. As Willi said, remove R0444, 0445, and 0459, connect the three pull down resistors to the 3.3v (L0631?).
I just want to thank everyone in this post, especially Mike and Willi for all the knowledge and effort. Here's mine and Willi's fix worked perfectly.
Mine is a 24 inch Apple Cinema Display. It was completely dark, although the fan was spinning, Megasafe was charging, USB worked, and the MacBook Pro's monitor briefly turned on and off while the Apple Cinema display flickered very briefly. I followed the service manual and found that very very dimmed image can be seen on the Apple Cinema when shining a flash light to it, this is a confirmation that the back light wasn't functioning properly. After getting a reading of 24v when testing TP81 in relation to the chassis ground, I decided to go with Willi's fix and gave it a shot (note that I'm not an electrician nor electrical engineer). And it worked, although the soldering was very difficult for me. As Willi said, remove R0444, 0445, and 0459, connect the three pull down resistors to the 3.3v (L0631?).
[http://i196.photobucket.com/albums/aa257/azntanan/Logic%20board_zpsdqkmrz05.jpg]
[http://i196.photobucket.com/albums/aa257/azntanan/Fixed_zpsy8ss1vu1.jpg]
And here's a link to the service manual if anyone is interested:
https://www.manualslib.com/manual/685572/Apple-Led-Cinema-Display.html#manual