January 9th, 2009, 09:31 PM #1
HELP!!!Apple Cinema Display 22" M8149
OK, to set this up, I have had my power mac g4 for about 2 years. Computer works fine, it's the display that is starting to mess with me now.
About 1 month ago, as I was rendering and left the screen alone, I noticed that the screen just went black, the power light started to shine really really brightly and steadily(not blinking)
I have had this problem a couple of times before with that type of power light signal, but that was due to sudden blackouts or power outtages, and I was able to fix that by waiting a few hours and disconnecting the power cord to teh mac and ACD, then reconnecting the ACD and power cord.
Now whenever I try to plug the display back in, all I get is the really bright power light shining and nothing else. And I have tried unplugging everything and then replugging everything and still nothing. As soon as I plug the ACD in or the power cord to the mac when nothing is on, the power button on my ACD immediatley turns on its high beam
I have searched literally dozens of forums and no one seems to have the same problem as me, just blinking or amber lights, but not a steady bright light.
I even read that it might have to do with the CMOS battery or a loose graphics card. So I replaced the battery and reseated everything that I could within the mac just in case anything was loose, and I still get the intense white power light and a black screen.
There has been a day or two within the month that the light won't immediately go on when I plug either the Mac or the ACD in and it will work normally....for about a couple of hours, and then shut off again on its own,
This leads me to believe that there is hope that I can fix it on my own. I just need the right knowledge and I am hope anyone on here can help
Thank you in advance
December 20th, 2010, 06:36 PM #2
I just read your post about the black screen and bright light from the power button when the display is switched on, realising that this happend to you in january did you find out what was happening and what the cure is, as the same things going on with mine.
Could really do with some help.
March 30th, 2012, 12:59 AM #3
I'm experiencing the same. Any resolution advice?
March 30th, 2012, 02:48 AM #4
After research i was able to find the problem and fix it, what you'll need to get is the Apple 22" Cinema Display M8149 LCD Controller. After already changing the inverter board with no change i came to the conclusion that was the one element left.
Apple 22" Cinema Display M8149 LCD Controller LM220W1
This is a tested and working 22" Apple Cinema Display ADC LCD Controller Board.
Model Number: LM220W1 CONTROL
Part Number: 6870L-C016F
This item works on Apple Cinema Display 22" ADC M8149
Anyway that was back in Nov 11 and the monitor is working like a charm. I was able to buy my LCD Controller on ebay,for around $17 or so not including postage; or you could try ifixit but they are out there.
I hope this helps, please let me know if you run into any problems.
July 16th, 2012, 06:54 PM #5
Thank you for posting a solution. I've been searching the internet for the better part of a day trying to find a solution to the exact same problem and ran across your post. I bought a new ADC to DVI adaptor, thinking that was the problem, as it was getting very hot. I received it today and unfortunately the problem was not fixed.
I just ordered a Controller Board from ebay and am hopeful that this will fix my issue as well.
Once I've installed the new board, I'll follow up with a post, hopefully confirming that it worked for me too.
August 20th, 2012, 09:58 AM #6
Controller board didn't work for me...plan B
Well, I replaced the Controller Board as suggested in a previous post, but that didn't solve the problem for me. It worked for a few hours, then back to the same bright light and no picture.
Someone else suggested replacing the main board, so I guess I'll try that next.