Toyota Repair: my 2004 Toyota corolla CE wont start, excessive corrosion, power interruption

Question
I have had my 2004 Toyota Corolla CE for about 6 months, it has about 55000 miles on it. The car has run just fine with no issues, Today after a few stops around town, I tried to start it and all the usual warning lights came on, radio on, dome light, etc. (the battery seemed to have ample power) But the engine did not turn over, click, anything. I checked the battery terminals and they had excessive corrosion build up. I cleaned them and I had to replace the clamp on the negative side (2 cables into the clamp) upon hooking up the positive side the alarm proceeded to go off. I got inside and after turning the key off and on a few times, it shut off (I might have pushed the little lit red button also to get it to shut off). The engine still doesn't start and I have both; charged the battery and even tried a new battery, I don't know where to go from here?

Answer
It sounds like the alarm system is causing this problem because of the power interruption so give this a try: disconnect the negative battery terminal, turn the key to the on position, leave the door open and reconnect the battery,try to start the engine.