Green Flashing light

Hello,
I am working on a Sony Vaio and I was checing it out and removing unwanted programs and desktop icons. I went to bed and the next day I went to the computer and plugged in the power supply cord sat down and pressed the power button. Nothing happened, upon looking at the back of the computer I saw a green blinking light. I have held the power button for 15 seconds and nothing. Is this the power supply or the battery that is bad ? I contacted Sony and they will not help all they said was hold the button for 15 seconds. Then they said to take it to a computer repair shop. I have been fixing Pc's for a couple of years and have never had this happen. Any advice would help !