Chosen Solution
My iMac late 2009 is running like applications and such will open but the LCD screen is black. I have put new thermal paste on the GPU, I have made sure all cable connections are tight, and I have even recalled the GPU solder. One thing I might think is causing it is that the GPU temperature cable is unplugged because its being a pain in the but to install. But, I’m not sure it is that because I have my fans running at high speed because HDD temp cable is unplugged because I recently upgraded to a SSD. Any answers are greatly appreciated. Thanks
Are you able to see an image on an external display? If you are then the GPU is fine. This then points to your internal display having issues. Using a flashlight placed on the display at a sharp angle can you see the faint image off your desktop and its icons? You need to fix the fans, you really need to get them connected and working. Here’s what you’ll need for your SSD OWC In-line Digital Thermal Sensor for iMac Late 2009 - Mid 2010 Hard Drive Upgrade
