Check this link out, it is for the Toshiba A45 S150 laptop.
This page has everything you can imagine for your laptop, including a service manual and owners manual which will make trouble shooting this device easy for you and cheap as well as there's no
cost for labor, just your knowledge and time.
Plus all the drivers are included on this and the alternate pages as well!
Here is the link.http://www.csd.toshiba.com/cgi-bin/tais/su...mily=1073768663
Good luck and hope you solve your problem, it is most likely a faulty power switch.
Please post back any ferther questions or let us know if your problem is solved.