Power Supply Question when Using Video Transmitter

On my drone, I have a VTx which is powered off the balance lead of one of the batteries. I was fiddling around earlier and noticed that if I connect up just the VTx, then the Pixhawk starts up too, as it is receiving power from the VTx via the Minim OSD. Is this normal? Could it create some issues? Obviously for normal flight, the Pixhawk gets it’s power via the power module which sits between the batteries and ESCs, but I’m concerned there could be some conflict.


It does not sound correct and most likely will cause issues as the power supply in the video side of the minimOSD is not that robust to begin with. Check it’s temperature when running.

A wiring diagram would help, or even a pic that clearly shows the wiring.
Have you cut the tracks on the MinimOSD?
(by your description obviously not but I have to ask)
What voltage are you using? Does the VTx run off 12v?

Details please.

Hi Mike, just to confirm I’ll get back to you shortly with details.

Hi Mike - just to update on this issue. I have since discovered that I do not actually need the power and ground connection from the Minim OSD to the VTX. It works just fine by connecting the signal wire only. I think it was working fine before as I typically powered up the VTX last when connecting everything before a flight (was using a balance lead off one of the packs) But on one occasion I powered up the VTX first which sent power all the way through the OSD and onto the Pixhawk and peripherals and I think I fried the OSD. I have now replaced the OSD and just use the signal wire to the VTX and all is fine.