[NTLK] eMate 300 board repair DZ1

[Brad Myhal]

Hello all.
I just picked up an eMate 300 which will run off its battery fine, but is
in need of repair because it was ran off of a non original power supply.
On the board there is a component marked DZ1 right next to the power input
that got very hot and is fried.  I am assuming it is a zener diode
to regulate the input voltage, it has markings on it "721 KV"  Can anyone
tell me the value of this component for sure?  Does anyone have a schematic
of the board?  I have a good suspicion that this is the only damage and if
I know what value this zener is I could fix it.
Thanks in advance.