Hi all
Trying to work out how to calibrate esc’s when I cannot connect using only usb power. It would appear that FC cannot be powered this way.
Can only connect to Betaflight (or computer) with battery plugged in is this normal?.
Because I can connect with battery plugged in I know it’s not cable or drivers.
In blheli I have “program by tx turned off”
I want to calibrate because motors don’ always start at the same time. Running Oneshot125.
thanks larry
Hey Larry,
There must be a Problem with your Cable or your usb port…
Normally you can power the Flightcontroller with only the cable…
Try to use another cable and another usb port on your computer…
Luca 
Yes, if your omnibus is not powering via USB then there is likely an issue… either its your cable, usb port, or it could also be your soldering that is causing a short somewhere. Could you send some photos of the top and bottom of your board so we can check… otherwise if you purchased form us send an email to support with your order number so we can get this sorted for you. If it does turn out to be a faulty board we will replace it for you.
Thanks Alex and Luca have contacted unmanned tech and have sent photos.
As I mentioned cable and port are OK as I can connect my other two quads no problem and can connect this one ONLY when battery is plugged in as well.
You blew a blocking diode. If you have an SMD Rework station, if you can identify the diode and if you can source a replacement, you MIGHT be able to repair the board.
The diode it was missing from board when I got it I just didn’t know it hence the confusion.
Would attach photo but don’t know how.
Any way have contacted UnmannedTech to identify the diode. They have been very helpful.
I found a work around to calibrate esc’s , it’s not ideal but it works.
I built a high/low dual SmokeStopper detailed here DIY - SAVE YOUR ELECTRONICS! BUILD A SmokeStopper ! - RC Groups.
With it I can power the board and connect to computer using low watt filament and program esc’s using both.
cheers