MacBook Pro doesn't start after changing HDD
I recently changed my HDD to another one in order to sell the MacBook.
After that it doesn't turn on anymore.
The only thing happening is that the white light turns on for a few seconds, then it goes off only to go on again. In this process the fan, the superdrive and the hdd make noises, so this isn't the problem, i think. This happens repeatedly until I shut it off completely with holding the power button.
I tried to rest the SMC, NVRAM an so on. Nothing helped. I also tried it without the HDD, with the old HDD also tried it without the RAM.
Anyone knows the Problem? May it be the Logic board? I am a student, so I don't have the money to replace it or even buyour a new Macbook.
I hope someone can help me.
Is this a good question?