2007 Macbook won't start

[irishjac]

I had my 2007 Macbook running on battery power and forgot to charge it, so it turned off. Since I plugged it back in, it will not restart. When I press the power button, no fans or lights start up.

So far, I've tried:

Resetting the SMC.
Removing the battery and attempting to start from AC power only.
Holding down power button while unplugged, then plugging in the power adapter while still holding down the power button.
Starting from another power adapter (with the battery installed).

A couple of other notes:

When I press the button on the battery, all the green lights turn on.
With the battery out, the power adapter blinks red.

The computer was purchased in September of 2007, so I believe it's running Tiger (but not sure). To my knowledge, there's been no water damage.

Any help or ideas would be very, very welcome!

 

[Detrius]

Are the power adapters the L-shaped ones or the T-shaped ones, and have you installed the firmware update?

 

[irishjac]

Are the power adapters the L-shaped ones or the T-shaped ones, and have you installed the firmware update?

It's t-shaped, and I'm honestly not sure about the firmware update. I updated it regularly, but it had been a few weeks since I had last checked for updates. Would the firmware update have shown up in the regular checking for new software (I'm aware of the contradiction in terms there)? If not, chances are I didn't install it.

Thanks for your help!