I also have a 2007 A1226 and had the same problem. It turned out to be the logic board. I am a certified technician so was able to diagnose it myself. After trying the hard reset (removing battery and unplugging from power, holding the power button down for 30 seconds, replacing battery into its place and plugging it back into power) and getting nowhere, I ordered a used and guaranteed working board from eBay for about $119.00, my Macbook Pro was back up and running with no more issues. I am still using it. In fact, I just upgraded the RAM to 4GB and it doubled the speed. Chances are, your logic board is bad.