Mavic 2 Zoom losing 2.4GHz reception - have to switch to 5.8GHz to make it fly

[Unlikely]

I am flying my Mavic 2 Zoom here And I find that the drone itself has effectively lost transmission on 2.4GHz.

- It is not a reception issue, as I am in Philippines on a piece of land with no other houses or electricity (only my offgrid solar which I have tried turning off.)
- I have both the RC1A controller and RM500 Smart Controller and have confirmed that it is the aircraft that is failing to make the 2.4 GHz connection.
- Nothing to do with phone or tablet attached, as I have demonstrated the fault when flying RC1A alone.

Even if I have the drone on the ground within 2-5m, I will frequently lose video connection if I leave the setting on Dual or 2.4GHz.
> BUT when I switch to 5.8GHz, then it can fly perfectly OK !

I also tried applying an FCC mod to increase the transmission power, and I can fly with 5.8GHz with constant HD Video Transmission at a range of 500m straight up, and also 400-500m around my house, but of course 5.8GHz is not good for any longer distances, so far as I understand.

I have disassembled the unit a few times (I am qualified EE) and cannot see anything obvious like a corroded antenna connection, so I am suspecting the forward leg antennae and thinking that I could try changing these quite cheaply and see if that would fix the problem. What do you think?

Certainly the alternative to change the Core PCB is way too expensive to be worth the effort. ($337 from DJI, plus shipping and some complicated fan mounting.)

Anyone got any ideas that they can suggest? Perhaps someone crashed their drone and found the reception was reduced until they changed the front leg antennas??

Or did anyone try installing that old firmware and getting the reception back? There are reports of reception being reduced after a 2021 firmware upgrade?

Thanks in advance for any assistance or ideas.

 

[Felix le Chat]

I am flying my Mavic 2 Zoom here And I find that the drone itself has effectively lost transmission on 2.4GHz.

- It is not a reception issue, as I am in Philippines on a piece of land with no other houses or electricity (only my offgrid solar which I have tried turning off.)
- I have both the RC1A controller and RM500 Smart Controller and have confirmed that it is the aircraft that is failing to make the 2.4 GHz connection.
- Nothing to do with phone or tablet attached, as I have demonstrated the fault when flying RC1A alone.

Even if I have the drone on the ground within 2-5m, I will frequently lose video connection if I leave the setting on Dual or 2.4GHz.
> BUT when I switch to 5.8GHz, then it can fly perfectly OK !

I also tried applying an FCC mod to increase the transmission power, and I can fly with 5.8GHz with constant HD Video Transmission at a range of 500m straight up, and also 400-500m around my house, but of course 5.8GHz is not good for any longer distances, so far as I understand.

I have disassembled the unit a few times (I am qualified EE) and cannot see anything obvious like a corroded antenna connection, so I am suspecting the forward leg antennae and thinking that I could try changing these quite cheaply and see if that would fix the problem. What do you think?

Certainly the alternative to change the Core PCB is way too expensive to be worth the effort. ($337 from DJI, plus shipping and some complicated fan mounting.)

Anyone got any ideas that they can suggest? Perhaps someone crashed their drone and found the reception was reduced until they changed the front leg antennas??

Or did anyone try installing that old firmware and getting the reception back? There are reports of reception being reduced after a 2021 firmware upgrade?

Thanks in advance for any assistance or ideas.

Sadly, this is not unusual. My own M2Z and M2P have exactly the same problem with no obvious physical cause. Like you, I have tried everything including a full teardown (to continuity check components, wiring and connections). Even tried available hack to boost 2.4ghz transmission power - no joy there either. The only thing I did notice was the signal dropout was abrupt and occurred directly after I upgraded firmware from *.*.0770 to the latest and last version.

I can now only fly with safety and confidence using 5.8ghz, to balance out the reduction in signal strength (I'm in a CE region) I've taken to running the signal boost hack permanently, which gives me a solid 26db transmission on 5.8ghz.

The furthest I fly out is usually 1700-2000ft, I don't ever fly long range. If I want to shoot a building, or landscape feature, I have always driven or walked close to target and then deployed on or near site. So far (touch wood) the 5.8ghz signal has been rock solid which means my two older birds still get used regularly.

 

[Unlikely]

Sadly, this is not unusual. My own M2Z and M2P have exactly the same problem with no obvious physical cause. Like you, I have tried everything including a full teardown (to continuity check components, wiring and connections). Even tried available hack to boost 2.4ghz transmission power - no joy there either. The only thing I did notice was the signal dropout was abrupt and occurred directly after I upgraded firmware from *.*.0770 to the latest and last version.

I can now only fly with safety and confidence using 5.8ghz, to balance out the reduction in signal strength (I'm in a CE region) I've taken to running the signal boost hack permanently, which gives me a solid 26db transmission on 5.8ghz.

The furthest I fly out is usually 1700-2000ft, I don't ever fly long range. If I want to shoot a building, or landscape feature, I have always driven or walked close to target and then deployed on or near site. So far (touch wood) the 5.8ghz signal has been rock solid which means my two older birds still get used regularly.

Very interesting. I wonder is there a way to install the earlier version?

 

[Felix le Chat]

Very interesting. I wonder is there a way to install the earlier version?

As a last-ditch effort, I'm going to use the available hack software to attempt to roll back to *.*.0670 firmware, apparently it's a bit of a faff, so I'll let you know the result. The strange thing is that this 2.4ghz 'glitch' happens with some Mavic 2's but not others. My controller is RC1A as well. I know that there is a hardware difference between this controller and the later RC1B, I wonder if this is a common similarity in the glitchy M2's.....

 

[Unlikely]

As a last-ditch effort, I'm going to use the available hack software to attempt to roll back to *.*.0670 firmware, apparently it's a bit of a faff, so I'll let you know the result. The strange thing is that this 2.4ghz 'glitch' happens with some Mavic 2's but not others. My controller is RC1A as well. I know that there is a hardware difference between this controller and the later RC1B, I wonder if this is a common similarity in the glitchy M2's.....

Yeah, I just spent a few hours on this, and failed.
I have upgraded to 0790 which has an ARB AntiRollBack of 2 for version 0790 so it appears not possible to Flash an earlier version
FYI I tried both Drone-Hacks and DUMLdore from Github.
Let me know if there is something that I am missing.

P.S. I have RC1A and RM500 controllers.

 

[Unlikely]

 

[Felix le Chat]

View attachment 165166

This was what I was going to try. I won't bother now. I was also considering forking out £500+ for a reconditioned smart controller in case the RC1A remotes were on the blink. After reading your comment, I will definitely save my money and carry on using boosted 5.8ghz. thanks for that info.