Last time we used our bot the crystals would not work. We tried other crystals. The bot worked tethered with a cord. What is our problem?
Your receiver (the yellow thing) may be bad. The cable between the receiver and the controller may be bad or not seated correctly. The antenna on the receiver may have somehow pulled out. The antenna may be rolled into a little ball and taped to the metal frame. The radio part of the transmitter might be bad. I guess it’s possible that one or both batteries might be very low, although I haven’t seen this cause otherwise undetected radio problems before.
Can you swap in another receiver and try that? Can you try a different transmitter?
usually when we have this problem the receiver is in the wrong rx port. Just another thing to check because whenever we change to the tether and back this is something real easy to forget to change.