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Hi, I bought a used imac 24”, late 2007, EMC 2134 (imac#2). It worked for a few days and then I get a black screen. When I am starting the imac, I hear the starting sound and fan but I always get a black screen. All 4 indicator LED lights are lighten. I tried and reset PRAM, change battery, remove all external devices and keyboard and unplug it for a while but nothing work. I also used a flashlight and lighten my screen trying to see my desktop but I didn’t (in case that was a back light issue as some people on the web stated). Then I connect it to an external screen I can see my desktop on the external screen. I have done some research on the web and I see that there are a few more things to try: a) replace the inverter board b) connect with a wire two specific parts, inside the imac, in order to give to the display the message to turn on Do you think that any of these suggestions would might fix it? I would appreciate if you have any other suggestions of what I have to try in order to make it work. I want also to mention that I have also one more imac 24”, late 2007, EMC 2134, that I had bought as new back in 2007 (imac#1). I also had a black screen on this. A technician told me that I had to replace the screen, another one told me is the graphic card. Only the three first LED indicator lights are lighten. Then is when I bought the imac#2. So I can take parts from the imac#1 and place them on imac#2, if it is a need. I also tried both displays in both imacs but I still getting a black screen in any combination (with imac#2 with all 4 LED indicator lights lighten and imac#1 with 3 first LED indicator lights lighten). I am not experienced with electronics’ repairs but I will give it a try. Please let me know if you have any suggestions. Thank you, Thodoris
Regarding the inverter, I tried to replace it but I didn’t manage to take it out completely as it has a blue “cord” connected to the inverter board and it looks like that I can not “unplug it” somehow.
You’ve covered the possible causes. In your case I would switch the inverters. This is the guide for the 20” but will work for you: iMac Intel 20" EMC 2133 and 2210 Inverter Replacement Inverter cable Apple part# 922-8236 LDVS Cable Apple part # 922-8162
Lets look at this from a different direction as I don’t think you have an inverter issue. If you did you would have seen the faint image of your desktop and its icons. As you can see an image on an external display that narrows things to a bad LVDS cable and/or the connector on the logic board. I often find the connector has been pulled slightly from the logic board which can make the connection sporadic. Also, I find the cable had been inserted backwards which tends to blow a few components. Lets take a few pictures here of the connector and the area around it. Sharpness it important here! So make sure you’ve got enough lighting and hold the camera still. Take one looking into the connector down directly at it from the front and then 45 degrees from each sides and lastly one looking at the solder joints at the bottom looking up at 45 degrees. post them here for us to see Adding images to an existing question
