Q: My imac turns on, goes to a loading screen, runs a script and turns off. How can i fix this?

Hello samson288,

Thanks for that info and choosing the Apple Support Communities. I know how important getting your iMac working! If I understand correctly, you are unable to finish starting up your iMac, and it shows a bunch of letters and numbers and then turns off. I recommend you use Safe Mode to start up your Mac so that it performs certain checks, delete system cache files, verifies your startup disk, and attempts to repair directory issues which can resolve issues like yours. Please follow the steps in these articles:

Try safe mode if your Mac doesn't finish starting up
Limited graphics performance in OS X recovery or safe mode

Cheers!