Hi Jasmeet,
I have same problem, I also tried two adapters with 5V 3A rating. Both
the adapters give more than 5.3V some times and reset beagleboard &
red led of starts to glow.
Actually as soon as voltage more than 5.3V beagleboard-XM over voltage
protection cut-off supply, till voltage becomes lower than 5.3V. Thow
most adapters I found are not suitable for beagleboard. It require 5V
+/-5% tolerance adapter and most adapter fail to meet this.
You should not try removing this protection, try to make your own 5 V
regulated supply, if not using usb ports you will be able to power it
from max. 350mA current.
Abhishek Mahajan