Sudden loss of communication, pwr loss on pixhawk, aircraft flips and crashes

Pixhawk
1

Hello,

This is my first post, please allow me some leeway, as I’m getting up to speed with the forums guidelines.

Here is the situation I’m having. I have a DJI F330 that I’ve built up with the Pixhawk 4 with PM07 Power Module, Raspberry Pi 4, and FrSky X8R receiver to communicate with the Taranis X9D Plus.

Up until recently, at least 4 months, the quad has been flying very well. No issues at all. It goes from being flown manually, with remote, and connected to a Motion capture system with autonomous flight application running via ROS depending on what we want to do with it on a given day.

Recently, I took it out for a test, and it suddenly did a 180 flip, and crashed. After replacing one of the frame arms, I started to dig into what could have caused the crash. So I started back with the basics, just flying it manually with the remote, no motion capture. I would arm the quad and throttle up and hover at about a foot off the ground. Within a few seconds it would then do its flip and crash. Typically when that occurs I would throw the kill switch, so as not to cause to much damage. However, this is what I’ve found out thus far.

It appears that the Pixhawk is actually losing power, or shutting down, two of the motors appear to be throttling down first, causing the flip, and then nothing. Each time the quad would flip, I would have to disconnect and reconnect the battery in order to get the Pixhawk & receiver powered back up.

I’ve connected the quad via a telemetry receiver to the QGroundControl software application to check if there are any errors that I could notice, but nothing pops up that I could see when it occurs. The flip and lose of power to the Pixhawk doesn’t always occur, but it does occur better than 60% of the time.

I’ve checked all the soldering that was done, and nothing is lose or damaged. All wires appear to be good. I replaced the power wire that connects the PM07 to the Pixhawk, just in case. I’ve pulled the raspberry Pi from the Mix, just in case, but I’m still seeing the issue.

I’m thinking maybe there is an issue with the PM07 Power Module, so I’ve ordered a replacement board.

Would there be any other options I should be looking at? Any log files that I could pull, that could offer me some more information on what is happening?

2

So I found the source of the issue. What was happening is I’m using a XT60 splitter for my power source. A single LIPO is powering being split to power the power management board and a Raspberry Pi4.

This is the Splitter I’m using. Well after replacing the Power Management board, I went to do a test flight. When I plugged the battery in, one of the ports on the splitter simply fell out. The only source of structural rigidity in the splitter is solder. Which really pisses me off. I would have thought there would be at least some wire running between the connectors. So I de-soldered the connectors, ran some wire between the connectors, soldered everything back up, giving it a little more strength.