MBP 15" won't boot -- how to rule out a keyboard/switch issue?

Is there a way to boot a MBP other than by using the power switch on the keyboard?

Last night I dropped my C2D 15.4" 2.4ghz MBP. I inspected it immediately and it booted up successfully. I then closed the lid and went about some other business.

This morning I discovered the battery was completely run down (one blinking light) and the machine wouldn't boot. When I say "wouldn't boot" I mean that absolutely nothing happens when the power switch is pressed - no fan movement, no lights, nada, zilch.

I connected the AC adapter and it stayed amber to indicate charging. However, even once the AC adapter light turned green and the battery showed a full charge, it still wouldn't boot. Tried a different AC adapter w/ the same results.

I kind of suspect a keyboard issue. I've taken the machine apart a few times to swap hard drives and the connection between the keyboard ribbon and the logic board is a little loose. Obviously when that connection is loose the keyboard and power switch are inoperable.

I opened the case and checked the keyboard connection and reseated it to no avail. (I also tried resetting the PRAM and PMU first)

Seems to me that it's not the I/O board since I'm able to charge the battery. That leaves me thinking it's either the keyboard or the logic board (eek)

How would you narrow this down further?