MCPX Tail rotor problem

[NiceBlades]

Hi all, just having a bit of a problem with the tail rotor motor consistently running from the moment the main battery is connected. Once bound the main rotor also works but the heli is unflyable. I know the way to determine if the main board has gone or the tail rotor itself is somehow defective is by trying another tail rotor, I just don't have one to hand at the moment and was wondering if anyone has had the same problem?

Tail rotor has been working previously, I have checked all board connections and tried with a fully charged flight pack. Also have tried to bind to the radio again but no change, all switches, gimbals etc havent moved since last successfull flight,

Any insight welcomed,

Ian.

[UKHelibob]

It sounds very much like you have burnt out the FET that controls the tail motor. The most common cause of this is a short circuit of the wires to the tail. The best way to check this is to measure the resistance of the tail by unplugging the tail from the board and measuring the resistance. You may actually be able to see the damage to the wires causing the short. Did the problem start after a crash or after maintenance to the tail perhaps ?

The FETs, 2 for the main motor and one for the tail, are on the front of the circuit board. They are square with 3 leads. Do any of them look burnt ?

[Leigh Beaumont]

This happened on friends msr way back heli had to be replaced, send it back to horizon they will sort it out there great

[NiceBlades]

Looked at the board and nothing burnt out and no burning smell, looks like I'll be calling Horizon! Thanks for the replies fellas.