Won't arm or change flight modes?

[Yorb]

I'm having an issue with my P3S: I can't arm, calibrate, change flight modes, or basically anything having to do with the actual quad platform. The RC link is good, GPS is good, camera feed and gimbal control are fine.

This started after a crash, I had to replace the yaw arm and it worked for a few flights but had a lot of brownouts (lost signal briefly and regained it). Then it started not arming occasionally. Now it won't arm at all.

I'm in the process of dismantling it again to see if anything is loose, but I don't really know what I'm looking for. I assume it's an issue between the receiver and the main board?

Any help appreciated. Thanks!

 

[epicdoom]

best advice at this point would be to check all connections like your doing make sure all are in place and clean. a crash can dislodge connections

 

[Yorb]

Resurrecting this to add some more detail, as the problem still exists and I'm getting back around to troubleshooting it.

• I can link (and relink) the controller to the aircraft via the app when the gimbal is connected
• I can control the gimbal with the controller
• I can get and maintain a GPS lock
• I can see current battery cell voltage in the app
• I cannot view IMU values (gyroscope, accelerometer, and compass fields are all empty)
• I cannot check or calibrate the IMU (associated buttons in the app are disabled or don't do anything)
• I cannot link (or relink) the controller to the aircraft when the gimbal is disconnected (via toggling S2 switch 3x; link is never established)
• I cannot use the sticks to arm the aircraft
• I cannot change flight modes using the S1 switch
• The iOS app shows "Good" for signal strength; the Android app flashes rapidly between "Good" and "Poor"

Based on what I've read, as long as the controller is linked to the aircraft I should be able to use the sticks to arm the aircraft even when the gimbal is disconnected. This is not the case for me, which I THINK indicates that the problem is not related to the gimbal.

I've read that the aircraft will not arm when the IMU is out of calibration. Since the app exhibits strange behavior related to IMU (see screenshots), that's what I suspect at the moment. I've tried the "tap" repair for the IMU, with no luck. The only other possibilities I can think of are the antenna or the controller, but I don't think these are at fault because:

1. Even with faulty antenna I'd think I should be able to communicate with the board when they're sitting next to each other,
2. I wouldn't see "Good" for signal strength if there was a connection problem,
3. The RC link is established quickly when relinking, and
4. I can control the gimbal without problems. (This may only indicate that the WiFi connection is good, but the RC connection has issues—I'm not sure how the wireless protocols work in tandem.)

Some screenshots showing blank sensor values, missing serial number and other oddities:


Posting this mostly for the benefit of anyone else searching for this, but if someone has any suggestions for what I can try/replace, let me know!