Chosen Solution
Hello I have iMac 21" 2011, it is working fine till yesterday. I was trying to boot it from USB but failed. After that I went to try a lot of options and read a lot of articles. One of them suggested resetting PRAM. I did reset PRAM and that was the end of my iMac. After resetting PRAM I only get black screen. I hear the startup chime and the keyboard is functioning and I hear sound when I click on it. What to do now, I never though that resetting PRAM can destroy then device
Please give us the model number and EMC number located on the botton side of the iMac stand. Hook it up to an external monitor and see if the GPU is generating a video signal. Why were you trying to boot from an external USB, what was going wrong?
Hi everyone EMC 2428 Model 21" mid 2011 I went for a workshop. The guy said it is GPU issue and he fix it using heat treatment . Now the system is loading but after the loading page it goes to black screen I just got fed up and for proving it, I asked him to do PRAM setting and after that the issue returned My conclusion is that I need to buy new one instead of fixing it
