Symptoms: Does not boot up.

Observations:
The POWER LED turns on for about one second, turns off for about two seconds with just battery attached.
When the Power supply is attached, the light by the power jack turns white, then orange like charging, and then off and back to white, then orange.
If I  disconnect the battery, and plug in the AC, the power light never turns to orange, but will blink periodically.
If I  reconnect the battery and do nothing, no lights go on.
Once I connect the battery, and press the POWER button POWER LED cycle (one second on, two seconds off) goes foerever.

After a few hours on this fellow I have concluded I am looking at a motherboard failure of some sort. 

When I apply a voltmeter to the battery, I see 12.28V when the LED is on, and a drop to 11.75V when the LED goes off. As the LED turns on, the battery momentarily (250-500ms) drops to 11.65V before ramping up to 12.28V for about a second before the LED goes off and the voltage drops back to 11.75V.

Nothing obviously burned.

It's a $400 laptop, and deciding if it is worth it to send in. Seems like it should be some failed capacitor or MOSFET, but I don't have any microsoldering gear. I could probably replace a surface mount capacitor but probably not a MOSFET. Any advice to further diagnose, or suggestions on an approximate repair cost/

By the way, THANK YOU for your video and providing this forum to do deep into component level repair. Thank you for sharing your experience and spreading your expertise. You have become my repair shop of choice.