Computer turns on, but not fully

[iwashere]

So I have gotten this laptop that would turn on every time I put in a little juice into it ie; battery, power cable. Now the confusing part is that when it does turn on the screen stays black. I've tried everything I can without changing the hardware (besides the HDD for testing) unplug, battery, holding on the power button, etc. It turned on fully once before, but as soon as i try to shut it down it stays on or shuts off then turns on again, yet it still doesn't show any sign of the screen turning on. I have also tried plugging in another screen. It worked and was the time it turned on. Both screens on so I imagine that the screen works fine. what do you think is wrong with this computer?

 

[scottiemedic]

If from what I gather, you are saying an external works but your LCD is black? Is the LCD completely black or if you put a flashlight to it, can you see a faint screen?

 

[iwashere]

No, both screens work when it's plugged in. its either both or none at all.

 

[scottiemedic]

When the AC adapter is plugged in? Have you had the battery looked at to see if it's providing the proper voltage to the laptop when on battery only?

 

[iwashere]

Yes, and im assuming the battery's dead. I don't understand why it turns on when i just plug in the ac adapter.

 

[iwih]

When does it stay black? before booting? after booting?! please, be very specific

 

[iwashere]

Sorry for the late post, but i found out my whole motherboard was fried... thanks for the help though guys. =D