Solution :
- If you face the laptop, lift it up and on the left hand side towards the battery there is a vent (not the large vent that stretches across the front). This is where I tapped it and it worked. Have to say though I needed to give it more than just a gentle tap before it started working. Nevertheless I am amazed that this worked. I though it was going to be off to the repair workshop for a few weeks.
- Disconnect everything, hold button down for one minute and listen carefully for a “click”. If it does not switch on, hold button down again. No need to remove battery unless several attempts as above fail.
- remove the keyboard and turn on without it