I have a mid 2011 mac mini model MC816LL/A with 6620 Radeon Graphic card. Last week I was booting it into Windows 10 through Bootcamp. Like always I got a message "Updating Steam" with a progress bar because this is something my teenage son has installed for his computer games. This takes a long time and I normally cancel it. But on this day I did not cancel it and it went on for maybe 20-25 minutes. Then suddenly the screen turned white with some horizontal lines in columns. The keyboard would not work so I shut it down with the power button. Now when I put on this mac mini I do not hear the normal chime when it boots. Now nothing appears on the screen. I can see the power on light and after some time I can only hear the fan noise. I tried to start it several times with the power button but with the same result. Kindly let me know as to what could have gone wrong with the computer and let me know as to how I can fix this problem.