How do I fix this short circuit?

Hey! A friend of mine gave me his broken Aviax F2 and said if I could fix it I could have it. The problem is that one of the motors does not run so I opened it up to see if I could find the issue. Lo and behold, when I applied a voltage across the windings of the broken motor on the board all the LED strips lit up instead. Disconnecting the LED strips merely caused a bright red LED on the circuit board to light up instead. Because of these two things I suspect shoddy wiring/soldering has caused a short circuit somewhere. Any ideas on further steps to take?