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Problem with HK Blue Series 85A ESC


Gremlin on the Wing
Hello all, I am trying to help a friend who has the HobbyKing Blue Series 85A ESC, and we have tried without success to program the Throttle Range.

We have been able to get the 2 starting beeps (at high stick), and the 2 conformation beeps (once the throttle has been lowered), however when we re-apply power to the ESC to test the throttle we hear the continuous "Bad Throttle Signal" warning tones.

We have confirmed that the signal from the Rx is working though use of servos, and have even been able to enter the program mode for the ESC options. I am truly at a loss for what might be the issue.

Any help would be greatly appreciated.

(We also tried, reversing throttle on Tx, checked that sub-trims where zeroed, and even tried setting throttle trim as low as it would go in both reverse, and normal.)


Active member
Are you certain that is a "bad throttle" warning tone? Could it be warning of something else wrong?
There is of course always the possibility that the ESC itself is faulty!