Tyro79's are setup to run your receiver on uart1 but After updating my tyro79 FC to newest matekf411 firmware my receiver ,though it's plugged into the same spot only works if I configure it on uart2 in betaflight. How is that possible?? Here is my FC

https://i.imgur.com/CWY10dPl.jpg

Here is my FC that link doesn't work.

It won't let me post a pic so it's the first pic in this link

https://intofpv.com/t-pre-build-tyro79-questions-fport

I do not have that FC and so I am going to make assumptions here unless you can provide me a copy of your old and new full CLI dump.

This can happen if the new firmware target assigns the uart to a different resource.

If you have the dumps can you compare the resource section to see if there is a difference in the pins mapping?

It looks like the Tyro79 has gone through at least 2 different iterations of the flight controller. Most seem to be based on the MATEKF411, but I found one post saying that it used a VGOODRCF4 target with remapped motors.

I realise it's probably not very helpful to ask this now, but did you take a CLI dump before you flashed it? Also did you definitely choose to 'apply custom defaults' after you flashed the board?

I figured that also kafie1980....I just wasn't sure that uarts could be remapped....It works now I was just thrown off by this ..took me forever to figure out what had happened. Thx for the response.

Now I'm having a problem where my fpv video will cut out for a a second and sometimes it comes right back, but if the video loss persists for more then about two seconds my drone just drops out of the sky. It doesn't loose full power( I don't hear the esc's beep) but the drone won't re-arm unless I power cycle it. I'm sooooo lost any input would help.

I would check the VTX antenna and wiring for any loose connections. Also check voltages at the VTX pads to ensure you are getting the correct voltage.