I have bought a OSDK expansion module for matrice 300 but the adapter does not feel right. After plugging into the osdk port, I measure voltage of power port and it is around 0.2V. And if I connect the computer and adapter board's usb port, the computer can detect nothing. I do not know if the adapter board malfunctions. Any advice?

[Updated]
I don't know if I actually solve the issue but it is interesting for those who may encounter the same issue. I opened the case of module and tried to diagnose where the issue is with a multimeter. After half a day of diagnosis and countless number of rebooting the drone, I could not see any obvious error on the module. I gave up and restore the module, and then gave a last try of reboot. Then everything becomes normal.  24V is back. The computer can detect the usb.

Wow! Thank God!

I think it is probably due to the bad contact at the OSDK port or the usbc port inside the module. I am not advising anyone to re-plug the usbc port inside as it may void the warranty but it was what I did before the module was workable.

Good Luck!

I'm facing the same problem with the 2 OSDK expansion modules I have. Sometimes it works, sometimes it doesn't. For both the 24V and the data connections (USB/API). Quite annoying. Does this problem still occurs with your system or is it stable from now on?

robert300 Posted at 4-12 05:27
I'm facing the same problem with the 2 OSDK expansion modules I have. Sometimes it works, sometimes it doesn't. For both the 24V and the data connections (USB/API). Quite annoying. Does this problem still occurs with your system or is it stable from now on?

Sorry, it is a late reply. It really depends on the way the usb-c is plugged. Although I don't see any real difference, plugging it harder does solve my problem.

After trying all the solutions we could find in threads like this, we discovered the problem was the round ribbon cable made by dji.  If you chop off the flange so it can go down further into the plug it will work.  This was true on multiple drones.