I broke my airunit antenna jack.

The correct replacement part for the jack:
Search Amazon for B08FSXZ3Z3

This will get you the correct jack.

It your not comfortable doing fine SMT work, then you might take the module and
the jack to a phone repair place and have them do it.

I did this repair under an assembly microscope with a soldering iron, not hot air.
(Hot air smt tools are at the office and I did not feel like driving there).
I think one with younger eyes (mine are 58) could probably do this with a magnifying visor or jewelers loupe and no microscope.

If you have a SMT hot air gun just heat up the part till it slides off easily and then clean up and resolder.
The real danger is lifting the trace under the center pin off the PCB.
(Even if you lift the trace, it might be savable see note later*)

With an iron I heated up the center pin till solder flowed well then lifted it from the PCB with tweezers.
I then examined carefully to see it was no longer touching the PCB at all.
At this point I put the iron on the body of the connector heated it up till it just slid off.

Once the connector was removed I used some solder braid to clean up the pads, resoldered, cleaned off the flux and reassembled.


*So you lifted the trace... bummer...
Now you need to find a real surface mount professional.
It looks to me like there is a small 402 series component before the antenna pin.
Most likely a decoupling capacitor. I believe that one could probably clean up the coating on the end of that component and put a very fine wire between the end of that and the center pin.
While this probably destroys the perfect 50 ohm trace impedance, the length is a tiny fraction of the
5.8 Ghz wavelength of ~5cm and should be ok.

Thanks for posting the part number. It seems quite common for people to snap the end of the MMCX off inside the socket. I Haven't heard of many people who've been successful in extracting that without ruining the socket and then needing to replace it anyway, or replace the complete DJI Air Unit.

I guess another option for people who aren't confident in replacing the MMCX socket on an Air Unit board is to just fly it with a single antenna attached, assuming of course that both antennas didn't break off. The Caddx Vista seems to manage just fine with one antenna so I'm sure the Air Unit would probably cope as well.

I have repaired one of these for a friend and it went okay, I have also just cut the plug off of the antenna and soldered the coax directly on, split the shielding to solder on both sides and the coax in the center.

Great tutorial, thanks.