I recently had this same problem with my mt6451. The wire in the AC charger went bad and the laptop ran the battery dead overnight. After fixing the wiring on the AC adapter and plugging in, all I got was 4 blinks of red on the battery light.
This is what worked for me. I will in no way be responsible if you should cause further damage to your PC.
The way I fixed it:
1. Disconnect all sources of power.
a. Main battery on bottom of laptop.
b. AC adapter
c. CMOS battery (it's not that tough to get to. Here's the manual.)
http://support.gateway.com/s/Mobile/...25_Service.pdf
2. Hold down the power button for a solid minute.
3. Reconnect the CMOS battery.
4. Insert the battery.
5. Plug in the power cord.
6. Look for the purple light on the front (it should stay solid purple. If it blinks on and goes off, wiggle the AC connection on the computer until it goes to solid purple.)
7. Leave it alone for a while.
8. After an hour or so of charging press the power button. You'll probably get an error screen telling you that the previous cmos settings failed or something like that. It's because the cmos was cleared when you removed the battery. Just reboot and you should be golden.
After completing those steps I was back in business. Hope it works for you too! Any questions just ask.