Syma Forum

I've had a very unlucky experience with Syma S107G. I bought two of them at a electronic stuff fair in my town.

After a few days the first one has gone. The motor moving the upper rotor (Motor B) began to spin slowly and eventually stopped completely. I opened the helicopter, checked for broken wires, jammed gears, but no luck.

But I had a second helicopter... After a few day it began to behave in a strange way: every now and then it seemed to loose contact with the controller for a fraction of second, sometimes with the helicopter rotating in one direction like one of the rotors stopped spinning for while and then resuming, sometimes with both rotors stopping and helicopter falling down. Most of the times I could resume the flight without a crash.

Eventually it began to do it when powered up: the helicopter shut down as soon as rotors started spinning. It was like an electric protection system was engaged: no response to commands, leds all off, and I needed to switch off and back on. This behaviour could be sometime avoided starting rotors gently.But after a charge, all motors began to spin slowly and the helicopter could not take off.

I tought it could be the battery, so I replaced it with the one from the broken helicopter.

Again, no luck. Motor A was OK, but Motor B began to spin slowly, like for the other helicopter, and eventually stopped.

I cut off Motor B wires and tested it against the battery: it was dead.

So I had two working motor A but no motor B. I took motor A from the first elicopter, moved very carefully the gear down along the shaft in the same position of Motor B, and mounted it connecting the blue wire of the motor to the white one from the PCB and the red to the black.

Well... IT WORKS.

I ordered a couple of replacement motors, hoping to revive also the other helicopter.

Any clue of what could be

P.S.

Motor B top is white, with black and white wires while motor A is black with blue and red wires.