iMac mid 2011 21inch black screen after cpu upgrade
So i have an iMac 2011 21inch that originally came with intel i5 2400s CPU, decided to upgrade to i7 2600cpu, even though it takes 95w of power instead of 65, people say its possible to do this upgrade on this machine. So, i followed guide on ifixit on how to change cpu and i assume i did everything very accurately. Upon first start, i hears usual startup chime, a screen backlit flashed on and off and then heard fans working hard but black screen. Held power button until it turned off and tried again, this time same scenario but no backlit flash - screen completely dark, heard start chime with optical drive sound and fans working hard. Im pretty sure its not the backlit turned off but something else. Checked all display connectors and they connected properly and are tight. Also tried the command option p r combo, i do hear iMac restarting a lot of times as long as i keep holding the combination. Once released - it supposedly boots up. Any suggestions? Put old cpu back?