Customer complaint: Forward works; reverse never engages

1. Identify the ESC model and whether reverse is supported; aircraft and some racing modes intentionally disable it.
2. Raise the driven wheels off the ground. Verify neutral, throttle channel trim, end points and transmitter direction.
3. Check forward/brake/reverse versus forward/brake settings. Some models require brake, neutral, then a second reverse request after stopping.
4. Perform manufacturer-specific throttle calibration and inspect fault LED or beep codes.
5. If still failing, compare with a known-good compatible receiver and motor only as permitted by the manual. Internal board faults require documented bench diagnosis.

Pass criteria: Reverse engages correctly after required sequence; forward, neutral and brake remain correct.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Customer complaint: Reverse works; no forward drive

1. Check ESC running mode, throttle channel direction and forward endpoint.
2. Recalibrate neutral/full throttle/full brake using the exact model procedure.
3. Check connector integrity and inspect for thermal or current-limit error codes.
4. If the symptom persists, isolate radio versus ESC using a compatible known-good receiver or signal tester.
5. Do not infer a particular failed MOSFET without verifying the power stage and gate driver.

Pass criteria: Normal forward acceleration without unintended movement.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Customer complaint: Vehicle coasts despite brake command

1. Distinguish drag brake from active brake; review running mode and brake percentage.
2. Verify transmitter brake endpoint and neutral calibration.
3. Check that reverse/brake timing is normal for the specific ESC firmware.
4. Inspect mechanical drivetrain and motor connectors for loss of electrical braking.
5. Escalate unexplained behavior to qualified power-stage inspection.

Pass criteria: Repeatable braking and safe stopping distance in a controlled test.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Customer complaint: Motor jerks or fails to start smoothly

1. Disconnect battery and inspect drivetrain binding and motor bearings.
2. Inspect all three brushless phase connections and solder joints.
3. For sensored setups, inspect the sensor cable, connector and supported phase order.
4. Check battery condition, motor/ESC compatibility, timing and current limits.
5. Test only with manufacturer-approved procedures; do not short phases.

Pass criteria: Smooth startup under light controlled load.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Customer complaint: No startup tones, lights, or steering

1. Remove battery and inspect polarity, battery connector and physical damage.
2. Check battery voltage with an appropriate meter and manufacturer-safe handling.
3. Check switch and wiring continuity only when de-energized.
4. If ESC starts but receiver does not, check BEC rating, receiver wiring and supported voltage.
5. If a short, swelling, burnt odor or heat damage is present, stop and refer for qualified inspection.

Pass criteria: Correct startup and receiver operation without overheating.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Customer complaint: Runs briefly, then cuts out

1. Read fault indicators and recorded ESC temperature if supported.
2. Check gearing, drivetrain drag, airflow and cooling fan operation.
3. Confirm battery cell count and motor specifications against ESC limits.
4. Inspect high-current connectors and solder joints with power removed.
5. Do not bypass thermal or current protection.

Pass criteria: Sustained operation within manufacturer temperature limits.

Workshop question: Which result rules out a transmitter setup problem, and what evidence would justify inspecting the ESC itself?

Reverse may be disabled by mode, require a second input after braking, or fail because of calibration and endpoint settings. Confirm settings and signals before power-stage diagnosis.

A BEC fault may remove receiver/servo power while motor switching remains intact; a motor-phase fault typically affects motor movement. Check model-specific status and voltage safely.

Severe carbonization, damaged multilayer board traces, sealed/potted modules without supported service procedures, uncertain insulation integrity or uneconomic repairs favor replacement.