Canon Pixus 850i

I got a broken printer Canon Pixus 850i.
Pressing power button get no result. Here's memo what I'm doing...

Quick google search gives me a hint to replace a ink cartridge.
Without power I couldn't touch the cartridge.

Then I also find a guide how to dis-assemble at http://plaza.rakuten.co.jp/highkikku/3000.

Thanks to this page, I could take out the white assemblies that masks two holes out of total 6 holes that is necessary to release the upper assembly.

Removing all cartridge didn't help the situation. Power button doesn't light the led.

I checked the power line that comes from the AC adapter from the bottom.

At the open load.
Even number pins are the GND. (Red, Yello, Blue)
Brown 5V.
Lightblue 24V
Green 27V
Purple ~2.5V (This is marked as CONT at the AC adapter)

At insertion of power connector to the board,
CONT line becomes 0.5V then other power lines seems to be OFF.

Ooop!
While checking the voltage when I pressed the Power botton,
:
:
White smoke and bad spell comes up.

I made short circuit some where ....

GIVE UP.