Toshiba Portege R835-P56X won't boot

[gubba02]

Toshiba Portege R835-P56X, Windows 7

I was watching an online video on the laptop on battery power and fell asleep. I woke up to a dead laptop.

Symptoms:

- black screen

- won't boot on mains or battery power

- no HDD, fan or other noises when turned on

- when powered on orange flashing LED indicates hex fault code "4Ah"

- WIFI LED is orange and constant

I have tried:

- holding power button down for 30, 60, 120 secs on battery and mains power - no result

- removed and replaced RAM

- scoured Toshiba and this forum but cannot find any answers.

Can anyone help with this problem please?

 

[ffg7]

remove main battery, disconnect power adapter, hold power button down for 20 count, re-install main battery, reconnect power adapter & turn laptop on.

 

[gubba02]

remove main battery, disconnect power adapter, hold power button down for 20 count, re-install main battery, reconnect power adapter & turn laptop on.

Thanks ffg7.
I have tried that (forgot to put it in the problem description) but no dice.