I'm having problems with my Raspberry Pi (2 different Raspberry Pi's actually).
I wrote the Raspbian IMG on SD using
dd on my Mac and Win32DiskImager on Windows.
I've downloaded it twice and I've also used two different SD cards, but neither start.
One of them had an old version (very old) of Raspbian and with that the Raspberry started correctly. What could be the problem? I know that both cards are compatible with Raspberry.
Just the red LED is switched on, while the green LED "OK" blinks for a while and than switches off.
PS: Using NOOBS instead of Raspbian I have no problem. How it is possible?