ISO standard fire lizard

took it apart to look for obvious component failure or mechanical damage in the motor drive area. didn't find that. what i did find was a tiny little ball of solder that had somehow managed to get trapped by a wire in between two pads which if bridged would tend to pull the motor speed up and interfere with servo operation. since it was an intermittent problem i'm not gonna say for sure that it's fixed, but i remediated a fault that i would expect to cause this problem and cause it intermittently