MacBook Pro boot, chime, but no video, no backlight, no power led.
I have a Macbook Pro A1278, which one, I tried to realize a internal cleaning and after reassembling, and turn it on, The equipment, boot, chime and the screen, flash for a second, but nothing else: the screen is black, no keyboard backlight, no power led indicator, fan, hard drive spin, light if Caps Lock press, even the Magsafe led is off.
I tried connecting a external monitor, and it works.
The battery since begining was dead, but, the laptop worked.
I already tried:
Reseting SMC, Reseting PRAM, Pressing Option key on start up. and nothing works :(
Это хороший вопрос?
I think that there is an issue with your backlight circuitry. Was it the cleaning that caused this issue?