Had a  close call yesterday. I was getting the King Tiger ready to patrol the perimeter against some of natures critters .When I plugged in my freshly charged 5000ma LiPo and closed the upper hull, the connector wires blew off .The resulting arcing fused the 2 pin connector to the clark base and melted the insulation on several other wires.
I yanked the battery out and tossed it into the metal bin ( cause you know it could start doing its own thing!)
Crap! Well what did I have to loose ,I pried the connectors apart and replaced them,rewired the ones with burnt insulation,put in a new battery and can you believe it the Clark survived !
I thought for sure it was the cheap power switch that  comes with most kits but it was still in good shape.
The silver lining to all of this, I discovered and fixed that whining noise was not from the amp but the recoil which was not coming to a resting position.
We love that tank.

Whew! that was a close one glad it turned out good

Always good to here good news , but if you got your negative still hooked up to on off switch , get it off there ! That is just the companys way of making a cheap connection, there is no reason for that ground to be on their

Ed, if the board survived and is working with the new battery, then chances are there was a shot somewhere near the power switch for sure. I would double check the wiring to the switch, and like Jughead says, make sure you move the negative off the switch also. Another thing I do is actually put in heat shrink tubing on the leads into the switch so there is no chance of anything coming into contact.

You probably haven't turn on the Clark board yet when this happen right ? That's why the board survived probably since the short is not from the board.

Whacky! As Mike said that is worth looking into.. hate when there's a short and a smoke cloud and you aren't exactly sure where things came from...