Sony Vaio VGN-N31Z/W not switching on

The symptom was first seen just after a lightening strike where the laptop was disconnected from the mains however it was connected to an ADSL modem which in turn was connected to a PSTN telephone line.  This could have been the source of the Voltage spike that could have damaged the laptop.

After connecting the power supply to the laptop there was absolutely no power, not even the battery LED, it remains dead.  I removed the battery and tried with just the power supply but still no power up.  The battery was discharged so it was useless to check power up  on the battery however I still tried but nothing positive.

Dismantling procedure.

1. Unscrewed RAM compartment to remove RAM and to see if there were any hidden screws and in fact there are.
2. Removed the 2 CDROM screws to extract the cdrom from the main chassis.
3. Removed 13 screws from the bottom chassis another 2 from the RAM compartment and another 3 from the battry section.  three other screws were removed from the CDROM section.
4. Unclipped the 5 keyboard clips to remove the keyboard from the top chassis section.
5. 1 hidden screw was removed from under the keyboard.
6. Removed the connection cable for the touchpad from the motherboard.
7. Removed the top chassis entirely so no I could see the top part of the motherboard.
8. Removed 3 screws that connect the Mboard to the bottom chassis.
9. Removed cable clip from the top section which also held the video and WIFI cables.
10. Removed two hard drive screws to release mboard.
11. Unplugged video cables from the mboard and other minor connectors.
12. The mboard could now be removed.
13. No visible physical damage can be seen however I tested if power was actually reaching vital parts on the motherboard.
14. The motherboard can be declared as dead. so it needs to be replaced.