Find the symptoms that best match your issue. If nothing does, please get in touch! Provide your full setup and a blackbox log if you have one.
Motors beep but won’t arm or spin #
If the ESC completes its normal startup beeps but the flight controller won’t arm, check the flight controller’s arming flags first.
If it arms but the motors don’t respond, or they don’t respond in the motor test, check that:
- the flight controller is using a supported DShot protocol,
- the motor outputs are mapped correctly,
- signal and ground are connected properly between the FC and ESC.
This is usually a configuration or signal problem rather than a failed power stage.
One motor stutters on startup; the others are fine #
Swap that motor onto another output.
If the problem follows the motor, suspect the motor: damaged windings, a rough bearing, debris around the magnets, or another mechanical problem.
Check the soldering where the motor wires are soldered to the windings. This will require removing the factory heat shrink.
If the problem stays on the same ESC output, check that output’s solder joints, phase wires, and connectors before changing ESC settings.
A motor stops or stutters mid-flight; the quad tumbles on a punch #
This is typical desync behavior.
Check, in this order:
- propeller and motor condition,
- motor bearings,
- phase-wire solder joints and wiring,
- then reduce ramp-up one step.
If it happens mainly at very high RPM, slightly more timing advance may help.
If the problem is mainly during recovery from low RPM, less timing can sometimes make the motor more forgiving.
See Timing advance.
Slow bobble right after cutting the throttle #
Most common on small, powerful builds.
Very fast deceleration can push the motors into a low-RPM region where there is very little thrust available and sensorless tracking becomes more difficult. When the flight controller asks for thrust again, there can be a noticeable delay before the motor produces it.
Try:
- a softer ramp-down,
- slightly higher idle if necessary,
- disable or raise the dynamic idle (if using Betaflight)
- and leave ramp-up alone if acceleration is already stable.
The full explanation is in Ramp, braking, and matching them to your build.
ESC very hot after normal flights #
Check the mechanical load first.
Too much propeller for the motor, damaged props, excessive motor load, or poor airflow can all increase ESC temperature.
Then check:
- airflow around the stack,
- PWM frequency,
- timing advance.
Try PWM frequency one step lower and leave timing on AUTO or test a lower fixed value.
Change only one setting at a time.
Motors hot, ESC fine #
Often this points toward the flight-controller tune rather than the ESC.
Excessive D-term or poorly filtered vibration makes the motors constantly produce tiny corrections that create heat without useful thrust.
Also check:
- damaged or unbalanced props,
- rough motor bearings,
- excessive timing advance,
- mechanical vibration.
If all four motors are similarly hot, look at the tune and filtering first. If only one is hot, look at that motor first.
Motors twitch or beep unexpectedly while disarmed #
Unexpected twitching usually points toward a command, signal, or power problem.
Check:
- signal ground,
- signal-wire routing,
- connectors,
- FC resets or power problems,
- and whether the flight controller is sending unexpected DShot commands.
Beeping alone is not necessarily a fault; some beep or beacon behavior may be intentionally configured.
RPM filtering isn’t working #
RPM filtering requires bidirectional DShot support and configuration on the flight controller.
Check that bidirectional DShot is enabled and that the flight controller is actually receiving valid RPM telemetry from all four ESC outputs.
ESC telemetry isn’t working #
RPM telemetry, EDT telemetry and serial Telemetry are different things.
Support depends on the flight-controller firmware and which telemetry features it implements. Not every flight-controller ecosystem uses every telemetry type.
For example, KISS does not currently use bidir-dshot telemetry.
Configurator can’t connect #
Check:
- ESC battery power,
- FC-to-ESC signal wiring,
- passthrough configuration,
If passthrough starts but the ESCs aren’t detected, retry the connection before changing settings.
Some flight controllers behave differently in passthrough mode, so connection timing can vary between FC platforms.
Flashing stalls partway #
Don’t immediately power-cycle everything.
Retry the connection first. If the ESC still communicates with the bootloader, flashing can usually be attempted again.
Make sure power is stable during the update and avoid disconnecting either the USB connection or battery while flash programming is in progress.
Smoke, a pop, or obvious damage on plug-in #
Disconnect the battery immediately and do not plug it in again to see what happens.
Take clear photos of both sides of the ESC before desoldering anything, then go through What your dead ESC is telling you.
After any soldering work, the first power-up should always be performed through a smoke stopper or power supply.
It flew fine yesterday, and now it doesn’t #
Ask one question first:
What changed?
A crash? Firmware update? New settings? Different props? Different battery? Motor replacement? Soldering work?
And think further back than the previous flight.
Some damage is delayed. A ceramic capacitor cracked during a crash can continue working for several packs before finally failing. A damaged motor wire can survive until vibration wears through the remaining insulation.
“It flew fine yesterday” tells you when the failure became visible, not necessarily when the damage happened.
