Laptop no screen + turns off after dozens of seconds
My Sony Vaio laptop displays nothing and shuts down itself after ~20 seconds.
I reseated the RAM, the CMOS and cleaned the fan nothing helps. I connected an external monitor through VGA and tried the Fn + F7 combination i get no screen. Yesterday I heard the Windows loading sound so i think it’s not a problem of Processor, RAM or HDD but something else. I also have attempted with and without battery and HDD and kept the vacuum cleaner near the cooler exit but it seems there is no overheating issue.
Do you have any idea?