Post originale di: anand_shail14 ,
I had the same problem but the answers mentioned here didn't worked for me.... And I am stating here what has worked for me. Note: 1) Boot chime sound was there every time I tried to start it. 2) Just 3-4 seconds after...the boot process was getting frozen. 3) I tried removing SDD and then boot from USB (ubuntu) , but it didn't worked. 4) Every time i started into device select on boot (Holding OPTION at the chime sound)... the spinner was getting stopped and the screen was getting frozen. 5) My model was MacAir 2013. 6) I tried every other answer mentioned here on this page Out of frustration when nothing was working out, I took out its motherboard ( a.k.a logic board ) and to my surprise I saw green colored corrosion... around one particular IC and resistor... everything else was working fine... but this green colored rust catches my attention. So with some plastic material i tried to shred off the rusted dust and used ALCOHOL (its chemical property it to evaporate taking water moisture with it) to clean it up...and then I left it in direct sunlight for some 1-2 hr to get it dried off thoroughly. Screwed it into laptop again and Voila...its working perfectly fine!!!!