Help a newbie! Recently purchased a Wraith rock crawler. Had issues with it responding initially, upgraded to Lipo batteries and it ran well...for awhile. My son recently ran it in the snow. It started making a grinding sound and wouldn't move. I noticed some sparking coming from the engine. We turned it off and let is sit to dry out. I hooked it up to a newly charged battery to try to run it and see where the noise was coming from. I figured if it was a broken gear or shaft I could simply replace it. However, I can't even get it to turn on now. Tried a different battery, still nothing. Any input on where I should start addressing this issue? Thanks for any insight you can provide!