Acer Aspire 5742 won't start [Closed]

Registration date
Friday August 31, 2018
Last seen
September 1, 2018
My Acer laptop won't start. I plug the power and the blue light for battery is on. I press the start button and nothing happens: no fan, no noise, no other lights, nothing!

Have followed your instruction to similar problem.

'switch off your laptop
Remove the battery
press power button for 30 sec
Reseat the battery again
switch on the laptop '

Tried this and still nothing.

Have cleaned RAM connections and swapped them in and out. 2 x 4GB Sticks.

It has always had a troublesome start button, have to push briefly at edge, not centre, so I installed new button board. Still nothing. Any ideas what to check next.