Vaio sve1513b1ew will not power on

[baalliso]

I have a Vaio sve1513b1ew laptop.

It will not power on. The charger shows a green LED, but the power button does nothing. The issue seems to be recurrent; the laptop was taken by Sony and fixed for exactly this issue a few months ago. It recurred a week or so ago, and I took it to a 3rd party computer shop (by now it was out of warranty). It was fixed within the hour. It is now not working again, and I'd like to understand how the issue is being resolved so quickly, and how I can do this myself.

I've tried the recommended removing the battery/AC adapter, and holding the power button down for 30 seconds. That doesn't seem to help. I've also tried reseating the RAM.

Thanks in advance for any advice.