MacBook won't boot, no chime, black screen, turns off then back on

So mine is the typical story of coffee spilled on a MBP. Immediately turned off and turned it upside down. I took the battery out and began to allow the parts to dry.

I took it apart and did a minor clean with rubbing alcohol and a q-tip. Got most visible liquid staining/corrosion off all circuit boards. I put it all back together and turned it on. Sure enough it turned on a booted normally, everything seemingly OK. Then after about an hour of being on it would randomly shut off with no warning. After holding the power button for a while it would finally come back on with the grey 'out-of-focus' screen and progress bar. Once that filled it it worked OK until the next random shut off.

So I thought I would more deeply clean the parts on the logic board and replace the keyboard and MagSafe circuit. I did this and went over most of the logic board with 99% rubbing alcohol. After all was dry and ready, I re-assembled it.

Now when I press the power button the light on the front comes on, HD spins up and fans turn on. After about 5 seconds it completely shuts off (HD clicks off) as if the power button was held down. Then by itself, it turns back on (fans spinning, HD spinning) but the screen remains black and nothing happens. It will sit like this forever with no action.

Did I somehow cause more damage to the logic board causing it to not turn on at all now?

I have re-seated the RAM, tried it with no RAM etc it does the same thing every time. Seemingly failing POST early on.

Any suggestions would b appreciated. Thanks