no power light

I have an AA1 D250 which started to fail with checkdisk getting stuck during rebuilding the index. As I was unable to get into the normal screen I decided on a restore. The first attempt was with 'restore and save data' - that failed so I tried 'restore - lose data'. That failed too so after googling I decided to follow the routine to flash the BIOS ( with hindsight a mistake). I prepared a bootable usb stick and copied on the BIOS files, booted into the stick and ran the flash - all went well, no errors and final message that flash had succeeded. The netbook didnt reboot itself but seemed to have switched off. When I pressed the power on button it didn't light up and nothing happened. Googled again and read that it may be necessary to disconnect the cmos battery, leave awhile and solder back. So I dismantled the AA1 reached the battery took it out (checked voltage 2.9) left it for about 4 hours and soldered back. Reassembled and pressed power on but still no light.

If the AA1 wont allow power up I guess I cant get at it to take any reccomended action re BIOS. I hope all is not lost and someone can suggest a way to get it alive again.