top half of screen is greyed out
The top half of the screen is greyed out starting at the center of the screen and progressively darker as it goes up. I hooked up an external monitor and it works fine. When first turned on the top of the screen flashes on for a second. I could also use a teardown of this model and where I can get parts for it. The only screen replacement I've found costs $699 and I don't know if this would fix the problem. I've seen a couple of other questions that refer to half screen problems but no real answers. I tried to buy an answer from Apple with no success. The machine is three weeks out of warranty.
I wanted to bring this question back up because I'm working with Miro to do a tear down and repair manual on this machine. We don't have one. I still don't have an answer that I know for sure will work and wanted to bring it before the attention of possibly some other contributors. I've subscribed to the Apple thread on this problem with no results. Any ideas? Thanks.
Seems to be a backlight issue. I think there are two backlight bulbs in the 24" iMac LCD screen so the top one could be bad or the inverter board for the top backlight. From what you describe the backlight try to power at boot up but only flash and doesn't light.
I have a 20" iMac EMC Number 2133 that has the same problem. It is about 3 years old and out of warranty. The top half of the screen is considerably dimmer than the bottom. It just started about 3 weeks ago. I started by ordering a brand new inverter and replaced it in my machine, same problem. I even flipped the inverter around and tested with different plugs into the top backlight and it was still dimmer than the bottom. The inverter I bought was from dvwarehouse.com and was claimed to be brand new, so it seems that the problem is the screen. I dont want to pay $500+ for a new LCD, I'd rather find a backlight and replace it on the screen, or if possible, buy a cheaper 20.1 inch monitor from a big box store and swap the screen out if it is compatible. If anybody knows how complicated/dan
I hope I'm not breaking any forum rules posting this on an existing question, I just wanted to contribute more information to the original posters question.
I had a similar problem. It was the top right of the screen was darker and steadily got worse. However it displayed fine on an external monitor. Try the flashlight test on it to see if it is the backlight. If the image clears up when you display the light on it then it is probably the backlight. In my case it was the inverter cable.
I don't know if this is relevant to the original problem asked.
I got the winning bid on a 20" imac 2.0 and went to pick it up, When it was brought out and turned on I noticed dark patches at the corners of the screen and mentioned it to the seller, who promtly walked into the back of the store and took out another imac, turned it on and no dark edges to the corners.
I think this points to variations in the screen manafacutre or rather bad quality control at the least.
So I was wondering if the dark half is really a back light issue and not just a LCD issue.
I wonder if you ever found an answer to your problem?. I have the same iMac and it's displaying the same symptoms. I described the problem to a Mac fix it company and they said it could be an Inverter issue or even worse, a logic board fault which they said was unlikely. They offered to sell me a Inverter board but I don't want to spend unnecessarily and find I do need a new LCD. So can you let us know if you ever got the answer?