I solved the problem with my own trick...
After all resetting whole of that sh!tty things like nvram or pram or smc... the problem not solved because the apple support wants the money! They need your money to grow up they told me we will fix this issue by changing logic board with 798$ with tax... im not in US and im in Iran we dont have any official center for apple devices but i traveled to Turkey for this because i had so important stuff in my mac book and i need them... so, i didnt accept they offer and wasted 5 days non stop. Finally my way worked.
Use whole that sh!tty reset options that you see on the google and appl dot com website.
(So look im Serious read it and do it my friend david from Uk just did it and solved his issue)
1-Turn off (ON) your macbook pro (=MP)
2-Turn it on in regular way and wait for chime
2'- if chime go to next level
2"-doesn't chime stay on abc level
A- turn on your MP wait for battery going to die; if the battery is dead and empty try to power up you MP by the power button, there's no chime or any thing i know; then click the battery recognition and if the green led blinks try again to power up and power let it to be full empty. (Or open you MP battery and empty that with electronic skills that i did it)
B- connect The power adaptor to MP and wait for fully charge, use the green leds to recognize it, wait for about 12 hours its better way.
1c-turn ON your mac with power button and immediately insert a cd or dvd init; wait for 10 seconds. Turn it off by forcing it, hold the power button (=PB).
2c-Turn it on by these trick:
Hold down the PB and Eject button together.
Let the cd eject.
3c-turn it of by holding PB. Turn it on and wait for 20 seconds then click the S word on keybord for multiple times.
3- the reason of black screen sometimes cause the lack of light (the back light) of lcd, use a mobile phone Flash LED to see the objects on screen, Approximate the outer light (the LED light or another lights) to the lcd and you can see the objects you can use the track pad or keyboard to fix your software issues.
If you cant see any thing or its white, blue or gray screen or the pure black like turned off macbook pro it is 100% the hardware issue.
The macbook pro i used the tricks is mid 2010, and 2011 for my friend.
Hope it helps.
Good luck and sorry for bad English grammar.
Questa risposta è stata utile?