No WiFi signal, can't pair with DJI Go, no fan spin

[Droning on and on...]

Thanks Detritalgeo for you help. I have 12V on that resistor/fuse. I tried freezing the gimbal area on the main core board and these 2 components heat up. Are you able to identify those? I might just look around for a broken board but it would be way cheap find just the components.

 

[Detritalgeo]

Make sure you have ~12V on both sides of the resistor/fuse..

I am pretty sure the 5-pin component is a voltage regulator. I am not sure what the smaller 4-pin component is.

 

[Droning on and on...]

Maybe someone is able to identify those components. SOT-23 package IC has CAXMHY marking and the other one (square, 4 pins) DF8 or 0F8 (not sure). Looks like the DF8 component is shorting 2 caps to the ground. Those component are also in other power sections on the board.



Detritalgeo, the fuses are ok. Checked both sides as well as continuity.

 

[Detritalgeo]

That will take some investigation, your CAX chip i have also seen with the 'LN8B' marking (LP5907 datasheet: http://www.ti.com/lit/ds/symlink/lp5907.pdf?ts=1590768655303)

Regarding the small 4-pin component, I have seen 'DF 6' and 'DF 7' as well but cannot find any info on the web just yet..

I wonder if these components represent an enable signal for the gimbal motor drivers?

We should contribute to the hardware page here: o-gs/dji-firmware-tools

Also as another test you can confirm voltage to the gimbal connector as shown below.. just be careful not to short something, fine-tip multi-meter probes are best.

 

[Droning on and on...]

Some wise people over dji-rev slack channel helped me.

CAXMHY - NCP114 (NCP114ASN150T1G or NCP114ASN150T2G)
DF8 - NCP160

I'm pretty sure these are correct as both input pins for these LDOs are connected together and there are caps that indicate they are both power regulators.

Back to my issue - I've identified a short on 3.3V rail in my Mavic Air. I will do voltage injection to see what heats up once my lab power supply arrives. What's interesting - now with 3.3V power rail shorted and previously 5V shorted to ground WiFi is not working. I swear this drone is cursed, I'm not sure how another power rail became shorted just by connecting the gimbal? :/

 

[Detritalgeo]

Thanks for the info. I will have to check that out, we should start a technical repair Discord server as well to share the knowledge.

I have an annoying board I am working on right now where the Wi-Fi enable is not working.. The 3.3V rail also has a short when not powered but can still generate the ~3.3V..

Sometimes I remove the smoothing coil to narrow down which side of the coil has the short but it can be a pain to find the right component.

 

[Droning on and on...]

I finally managed to remove the short from 3.3V line. I had to remove both LDOs mentioned above. They appear to power front vision sensors as they are reporting errors right now. Not sure if they affect the gimbal but it's still not working. I ordered new power regulators and will continue the repair once I solder them. Thanks @Detritalgeo for all your help. Can you contact me privately? I will let you know where we can share our repair knowledge.

 

[chiefwigms]

Did you ever get the Air to show up in debug mode with 1.1.2? Trying to do a motor test, but it only shows up as a Mavic Pro "orange30"

 

[chiefwigms]

got to it - in basic settings, you can set the air frame and then try all the motors

 

[Detritalgeo]

Was the Mavic Air actually supported in version 1.1.2 or was that before it was released?

 

[brunosardao]

Thanks a lot. I think it will be pretty helpful in the future! My Mavic Air has been fixed I did a short circuit test on 5V rail by freezing the motherboard and found the shorted capacitor. After removing it WiFi and the fan came back to life. My drone is 99% working right now. I'm waiting for a new gimbal assembly and it will be almost like new since I've also swapped whole case from the dummy unit.

Hello there, could you help me, I think I have the same problem, my fan doesn't spin, and I got solid red status led, the fan will start spinning after the motherboard gets to hot!! Can't get it connected to the RC or phone, since I can't use the status button to change it's connection type.

 

[EMDdrone]

Hello my name is Wilson.

Could you show me which was the capacitor that was shorted and did not allow to start WiFi or fan.