i am using Sony Vaio VGN-NR310E with Windows 7. Every time i try to switch on my laptop, the power lights keeps blinking and laptopn shuts down with a beep within 5-10seconds. Sometimes ut reaches the homescreen but then again beep and system off. Tried plugging out my battery , draining the battery and then restarting it with ac supply + battery but all in vain. Please help