Shorted power button **or** fried logic board? [VIDEO]

So my son says he was using his laptop and out of a sudden was prompted to restart/shut down/etc. Eventually the computer shut down on its own and since then has not passed from the apple progress power up screen.

Please refer to this video:

Already tried with no success or change in behaviour:

• Swapping the hard drive with that from another working MBP
• Swapping RAM modules with those from another working MBP
• Reseting PRAM and SMC
• Starting up in Safe Mode

In all case, I'm always getting the same behaviour.

I believe the issue may be shorted power button (also, considering my son says the problem began when he was randomly prompted to shut down the computer. That said, what I find odd is that the computer completed the onboard diagnostic utility without shutting down and it responds when pressing the power button to turn it on.

Thank you again for your input.

UPDATE:

My son just "confessed"... there was a part of the story that was missing... he says he was cleaning the keyboard with a Windex-like product and did a squirt or two directly on the keyboard when the problem began.

At this point I'm wondering if replacing the keyboard would fix the issue; I know the power button is connected to it. I'm also wondering if there is an issue with the logic board (but again, booting directly to the diagnostics utility COMMAND + D yielded no hardware errors). I notice that upon booting the computer fan runs at full speed and am also noticing that the magsafe power cable led is always in "green" (never in "orange"). Don't know if these are telling sign of possible logic board damage.

Thanks again for your input.