Chosen Solution
I recently upgraded the RAM in my mid 2010 27” iMac and now it just boots to a blank white screen. I’ve tried everything multiple times. Resetting the SMC, NVRAM, booting into recovery, booting off an external drive. Putting the original RAM back in it. Then trying all the above all over again. All I get is a white black screen!. No apple logo, nothing! It won’t even load boot options when I hold down the option key. The iMac was working perfectly until today. Does anybody have any clue what could be the problem? I’ve searched the forums here, tried every solution, googled my issue and even went through the YouTube tutorials but every tutorial assumes that the iMac should at least show the Apple logo when trying to boot up, or at least that it will give me a boot selection screen when holding down option on startup. I’m very familiar with all of those tricks because this isn’t the first time I’ve had a Mac with a similar issue but it is the first time that I literally get nothing whatsoever but a blank, bright white screen. My thought was that it could be a graphics card issue but this iMac has never shown signs of a graphics issue and the only thing that coincides with the issue is a routine RAM upgrade that I’ve performed many times over the years on every Mac I’ve owned. Could it be possible that something could have suddenly happened with the video card at the same exact time I upgraded the RAM?
Are you sure you got the RAM fully seated and using proper antistatic precautions? What does the onboard diagnostic LED’s telling you? Locate the black covered taped area in the bottom left corner
Here’s a breakdown of the onboard diagnostic LED’s meaning: LED 1 - Indicates that the trickle voltage from the power supply is detected by the main logic board. This LED will remain ON while the iMac is connected to the AC power. The LED will remain on even when the computer has been shut down or put to sleep. The LED will turn off only if the AC power is disconnected or the power supply is faulty. LED 2 - Indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is working correctly. LED 3 - Indicates that the computer and the video card are communicating. This LED will be ON when the computer is communicating properly with the video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the video card might be installed incorrectly or need replacement. LED 4 - Indicates that the computer and the LCD display panel are communicating. This LED will be ON when the computer is turned on and video signal is being generated. If the LED is ON and there is no image on the LCD display panel, the LCD display panel or inverter might be installed incorrectly or need replacement.
