Hi Daniel,

You may wish to try the following which involves opening up the laptop.

1.Try re-seating the RAM modules, see if it starts

2.Disconnect the battery, hold down the power button for 10 seconds to drain any residual power, reconnect the battery and see if it starts.

Here is a link which shows to to open your laptop.

https://www.youtube.com/watch?v=XdzsayVU...

If the above do not work it may also be something as simple as a faulty power button on the laptop. If it is connected via a flex cable to the motherboard (cannot quite see it properly in the video) you may be able to either test it with an Ohmmeter for continuity when operated or simulate it being operated by placing a momentary short circuit (bridging the connection - hopefully it is only 2 wire) across the connectors and see if it starts.

Hopefully this is of some help.