Do as Gary ( Max -U52) suggests and take the top and unplug everything but the motors. Try running the tank and see what happens. IF the RX18 is fried you can buy one for about $25 from Mato in Canada, or I have them as well.
Gary
Shipping into the USA for Canada Small Package Air is Less then $10 no insurance
Same package shipped with tracking and $100 insurance is about $16.00
I can actually ship things into the USA cheaper then I can mail something across Canada. I use the small package air option a lot. Not sure if the USPS has a similar option going into Canada, but it might be worth asking if you should have to ship something north.
Cheers