If you have a multimeter, check the out put of the board with the heat sink to see you are getting 9V out. This board is just your power supply, and powers the lights and feeds the motor circuit.
The real bugger is probably that EMD811 'bug' on the other board. It's a low current part for switching direction and made for 'toys'. Sometimes these devices get 'stuck' on when they burn out.
http://www.elite-ent.com.hk/up...11_&_812_v02.pdf
This part will only handle .6 amp - maybe.
I notice that they make a higher power part (EMD812), but soldering a surface mount component is harrowing.
Too much info? I'd go ahead a hack with a DC power supply and the double pole switch discussed earlier.
Jim