Order #706133 - Happymodel Mobula8 Analog Elrs - No Video Signal

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1

Order Number: 706133
Product Name: Happymodel Mobula8 Analog Elrs
Brand: HappyModel
When flying my Mobula8, I experienced a sudden loss of video signal and have not been able to recover it since. All other functions on the drone are working, it binds and flies perfectly fine, just without a video signal. I suspect the problem is with the VTX rather than the camera, as no OSD shows up on the goggles, only static.
I’ve re-flashed the flight controller, but it hasn’t had much of an effect. The video transmitter tab on Betaflight shows ‘Device Ready - False’, and I still have no video signal. Not sure on how to proceed; as I understand it the Mobula8 has a VTX integrated into the FC/ESC board, but there’s no signs of damage anywhere on the board.

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2

Hardware Check

The Mobula8’s AIO (All-In-One) board has been known to experience VTX-related failures, sometimes after minimal use or minor crashes. When the VTX portion of the board fails, it can manifest as a complete loss of video signal while other functions remain operational.

Diagnostic Steps

  1. Check if PIT mode is enabled (this disables video transmission)
  2. Use the Lua script on your radio controller to change VTX settings, as Betaflight control is currently non-functional
  3. When testing, use a LiPo battery instead of USB power, as this provides better video signal quality

Additional Diagnostic Steps

Power Supply Check

  • Verify if the 12V BEC that powers the VTX is functioning correctly using a multimeter
  • Check for any loose or unsoldered connections, as the VTX power and ground wires have been known to detach from the board

Software Verification
The “Device Ready - False” message in Betaflight is a known issue related to the firmware bug. This occurs due to:

  • Incompatibility between VTX firmware and Betaflight
  • Inability to control VTX settings through Betaflight
  • Required use of radio’s Lua script for VTX configuration

Potential Solutions

  1. Try powering the VTX directly from the battery to rule out power delivery issues.
  2. If possible, check the VTX temperature during operation, as overheating can cause failure.
  3. If these steps don’t resolve the issue, we will reach out to Happymodel to get some more info if they know of a solution to this, otherwise we will requrest they issue a replacement AIO for you under warranty.
3

Hi

Further to this, we have had an update from Happymodel:

The mobula8 spi elrs version is not MSP protocol vtx , its VTX Smartaudio

So you need to change port settings like this picture , and go to CLI command then copy the commands

|711x169.8

# vtxtable
vtxtable bands 6
vtxtable channels 8
vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 5725
vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E FACTORY 5705 5685 5665 0 5885 5905 0 0
vtxtable band 4 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 5880
vtxtable band 5 RACEBAND R FACTORY 5658 5695 5732 5769 5806 5843 5880 5917
vtxtable band 6 LOWRACE L FACTORY 5333 5373 5413 5453 5493 5533 5573 5613
vtxtable powerlevels 5
vtxtable powervalues 10 2 14 20 26
vtxtable powerlabels 0 RCE 25 100 400

set vtx_band = 4
set vtx_channel = 1
set vtx_power = 5
set vtx_low_power_disarm = ON
set vtx_freq = 5740

save