Order #721019 - Speedybee F405 V4 55a 4 In 1 - ESC failed one by one

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1

Order Number: 721019
Product Name: Speedybee F405 V4 55a 4 In 1
Brand: SpeedyBee
Summary of Issues with My 6S Build

:hammer_and_wrench: Hardware Setup:

• 6S quad with a 4-in-1 ESC. SpeedyBee f405 and 50A ESC

• DJI Goggles 3 + O4 Air Unit for FPV.

Frsky XRS RX

• Using a ribbon cable to connect FC and ESC.

:fire: Key Issues & Timeline

:one: Initial Power-Up – Motor Burned Out Immediately

• First time plugging in the battery, one motor instantly smoked.

• Other three motors seemed fine initially.

:two: ESC & FC Behavior After Motor Failure

• Used a multimeter to check the ESC → No shorts found between motor pads or battery pads.

• Removed burnt motor.

• Used a smoke stopper to test power-up:

:white_check_mark: 2 motors beeped and spun up in Betaflight.

:x: 1 motor didn’t respond.

• Connected to ESC Configurator:

• Only detected 2 ESCs instead of 3.

:three: ESC & Motors Gradually Stopped Responding

• After multiple power cycles:

:x: The working motors stopped spinning completely.

:x: ESC Configurator no longer detects any ESCs.

:four: FC Connection Issues

• FC LEDs light up when powered.

• Having trouble connecting to Betaflight via USB (only works sometimes).

:mag: What I’ve Checked So Far:

:white_check_mark: ESC has no visible shorts (tested with a multimeter).

:white_check_mark: FC powers up and LED lights work.

:white_check_mark: Checked ribbon cable

:white_check_mark: Removed ribbon cable and direct soldered between ESC and FC

:white_check_mark: Tested with smoke stopper (prevented full current draw).

:white_check_mark: Tried reconnecting multiple times.

:white_check_mark: Reflashed FC with clean install of Betaflight

:question: Questions for Troubleshooting

  1. Would a damaged ESC prevent all motors from working, even on good channels?

  2. Does the FC connection issue suggest power regulator damage?

  3. Could a faulty ESC cause gradual failure of the remaining working motors?
    https://youtube.com/shorts/jDqhvXNe-4M?si=P5HySwldHomBbxz1

Video link to issue here.

Image Description
Image Description3024×4032 3.8 MB

2

Hi Daniel good day,

Hi good day,

Thanks for reaching out to us!
Sorry to see you are struggling with your stack. What you are describing seems a bit odd, so I have emailed your description and video through to SpeedyBee and asked one of their engineers to give us some feedback.

As soon as I hear back from them I will update you.

Hope this helps.
If there is anything else I can help with please do let me know?

Regards,
David

Unmanned Tech Support

3

Thanks for the reply.

See what they come back with I guess.

Thanks