Help Please! Arduino Mega ADK and GSM fried..IT HURTS ;(

Anyone please i need your help because yesterday I was building my project using the Arduino Mega ADK with Arduino GSM Shield mounted in it. My plan was to use an adaptor as it power source instead of the USB.

THE SCENARIO WAS:
After I had plug in the adaptor, the board got overheated and quickly unpluged it. I know it got overheated because it smells like burning electronics and I knew somethings goes wrong. When I came to investigate if it does still works, I tested my ADK
by plugging it in my computer, unfortunately my computer was unable to detect the ADK despite the its power is on.My GSM also doesn't work, I tested it by mounting it in my Arduino UNO and had uploaded the Arduino GSM program built-in in the Arduino IDE.

Before the bad event, I checked the web about the specification of the ADK and it says recommended(7-12V) and the limits are at (6-20v). You may check on this site.

http://arduino.cc/en/Main/ArduinoBoardMegaADK

Being aware with the voltage input and having the limited resources, I used the adaptor of my Creative SBS A300 Speaker which has the following specifications.

INPUT AC 100 - 240 V 50 / 60 HZ
OUT PUT 11.5V AC 1600 mA

You may check this for further information.

Given the information, I would like to know where is my fault so it may not happen again but I do believe that I did follow the requirements in operating the microcontrollers.

Please give me information what had happen, the fault, if their is a way to fix it, warranty or anything. Please consider my current location, I lived at Philippines. Thank you very much for giving time for reading this. I am looking forward for your comments and suggestions. I had attached an image of it .Ouch! cannot help my self seeing it unoperational.;(

@jrom1384

EDIT: I see now that you have used an AC adapter. That was bad. Must be DC output.

That was a sad story. I would recommend that you contact your supplier and/or arduino sales support http://arduino.cc/en/Main/ContactUs. I cannot see that you have done anything wrong. My guess is that the regulator was overheated due to the 5-7 W it had to dispatch.
I hope that you will get it replaced.

Cheers!

Oh!..so it was really my fault. And I was so dumb to neglect that it was an AC.and I didn't know that, how careless I am.I thought all adaptors output were DC. This is really sad!!. I do still have a lot of plan for this..expensive though..but given the budget I would still purchase this..I think the warranty is void already upon purchase because they informed me that It has no warranty, since I want to learn arduino and further enhance my skill I take the risk purchasing it and believed that no problem with the item. Thanks bro for the information , It will not happen again next time..