If lights are flashing, then hardware is failing. Take it to a technician!
If you wont to try to fix it yourself, the first thing to do, is REMOVE the RAM, and try to boot. Does the indication change? If so, then re-insert ONE RAM, and try to boot again. IF it does not change indication with no RAM, then the Motherboard is bad, and I would encourage you to get a new laptop, and have a technician recover your data from the first HDD!