I forgot to add that the engine stuck in the sand was extremely hot when i recovered my drone. Probably due to me forgetting to disarm at first. And TX power was set at 25 mW, that didn't help with the ELRS signal, obviously. But IIRC, 25 mW (unless you have a Ham license) is the max power i can legally use here in the netherlands

I was flying LOS with a monitor, but as soon as i heard the telemetry lost warning i looked at my monitor and it too had gone. So I don't really know what i lost first. Both seemed steady enough right before the crash and all of a sudden the link quality of both dropped.

I was flying in a big open field in a forest, so definitely not an urban area although there are a few cell towers in the area.

And there isn't any obvious smell or damage i can see without getting everything out. I will do that tonight, when things have cooled down a little here..

I'll let you into a secret. No FPV pilot flies on just 25mW of power unless they are at a official race event or are indoors flying tinywhoops, even in countries where 25mW is the legal limit. The chances of getting caught are next to none unless you do something really stupid, and being out in the middle of nowhere isn't going to interfere with any other RF communications to be significant enough for anyone to be bothered, let alone actually try to find the source of that "illegal" power level broadcast.

As a side note, if the EU laws are anything like in the UK a HAM license means nothing for unlicensed transmissions to an airborne device (drone) on the 2.4GHz / 5.8GHz, and 900MHz frequencies. Even if you have a HAM license VTX on your you are still legally restricted to only 25mW when flying a drone.

It is also worth always getting into the habit of recording DVR if you have the option to do so which will include all the OSD telemetry data for analysis later if need be. Unfortunately there is no blackbox logging capabilities on the tiny 16x16 GEPRC flight controllers, but with ELRS you do have the option of logging telemetry data on your transmitter for further additional post-flight analysis if needed so you would then be able to determine from the logs if the dBm value significantly dropped to a failsafe level before the RC link was lost and your quad fell out of the sky.

I know

I had it set at that level out of an abundance of caution because my neighbor across the street has a ham license and an antenna farm on his roof, but i forgot to set it higher when i went out to fly..

As for DVR, i used a Skydroid 5.8G USB receiver to record, I wasn't planning on flying with goggles so I didn't bring them.. It would have helped if i had remembered to remove the lens cap. (I'll add "Check lens cap" to my pre-flight checklist.. ) See the video below:




A pic of the board:
   
The defective motor is on the bottom of this pic.

I was playing around with the OSD, I'm still not very sure on what info is nice to have on the OSD, and the OSD seems a little weird. I enabled the crosshairs but all i get on the Phantom are these weird brackets? I think this is due to an older version of betaflight running on the FC?

And for ELRS telemetry data on the transmitter, is this on by default or do i have to enable it somehwere?

If the image of the ESC you have shown is after you have cleaned the board then one of the MOSFETs looks bad (top right next to the stand off).

Looking at your OSD I will suggest you upload the fonts in Betaflight OSD again.

As a bare minimum you should have battery voltage, LQ, RSSI_DBM, OSD warnings.

To store telemetry on the radio you have to enable this for every telemetry sensor in the OpenTX Telemetry page.

That was just some gunk, i just brushed most of the sand with a anti static brush. After cleaning it up with alcohol the ESC looks like this:
   

For telemetry logging, all telemetry sensors are set to be logged by default unless you explicitly switch their logging option off, but nothing will get logged unless you configure the "SD Logs" Special Function with a specified time interval to start logging on a specific condition. I suggest you set it up to only start logging when your Arm switch in the armed position rather than for it to be permanently on and logging all the time. See the article linked to below regarding the "SD Logs" special function...

http://rcdiy.ca/aa-enabling-sensor-telemetry-logs

As for the OSD elements it is really down to personal preference. Below are what I currently have set up on mine along with how they are laid out on the screen. If you ever get any weirdness with font characters then it will be corrupt font configuration so just go to the "Font Manager" and click the "Upload Font" button to fix that. You will need a LiPo plugged in to successfully re-upload fonts to the onboard OSD chip.

• Battery current draw
  
• Battery current mAh drawn
  
• Battery voltage
  
• Craft name
  
• Disarmed
  
• Fly mode
  
• Link quality
  
• RSSI dBm value
  
• Timer 2
  
• Warnings
  

Aha. I was just looking onto that and noticed all of the sensors had logging enabled. After some googling i found the site SnowLeopardFPV linked to, now i have logging set up, and while i was looking into this i also found out how to enable screenshots:
   
Thinking about it, i might use my arming switch to start logging instead of the current switch, SC. I use the middle position of SC for screenshots

Sorry I was not too clear earlier but I replied in a rush.

Good thing you found the SD Logs function as Snow pointed out.

Setting it up to activate with the same switch you use for arming is the best option and this is what I do on my radio.

About the motor; the windings inside don't seem damaged (to my untrained eye at least) and it turns normally without grinding noises. I did a continuity test with my voltmeter on the motor wires and that seemed ok.
   

The thing with motor windings is that the wire is enamel coated and if the motor gets too hot then it burn the enamel exposing bare wire.

A badly burned motor with show black windings and smell terrible. But slight damage to the windings may not surface to the visual eye and over time or in another crash or hight throttle maneuver can cause damage.

Apart from continuity, one other test I recommend you perform is spinning the motor with a electric drill at the lowest power setting and measuring the voltage across each one of its 3 phases. As long as each phase produces more or less the same voltage or similar to a good motor then it should be fine.

JB did a video on this:



If the motor is fine then you will need to move over to the ESC and do some tests to ensure none of the MOSFETs are damaged using a multimeter to test continuity.

DrainMan did a video on this:

Did you already try swapping that motor over with one of the other known good ones? If not then I would do that first as it will determine if the issue is with the motor or with the ESC that motor is currently connected to.

I swapped motors #3 and #4 (#4 is the bad one) and #4 in the #3 spot has the same issue. It also gets really hot, too hot to touch.

Or in short: motor #4 is kaputt.

That's unfortunate. In a way it's probably better that a motor fried itself rather then the ESC board. There is probably some burnt windings internally that you can't see where the enamel coating has burnt off the winding wire which is causing a partial/intermittent short. There's not much you can do other then rewind the stator with new wire (which is a very fiddly job) or get a replacement motor. The latter will be the easiest and cheapest option.

On a related note, do you happen to have a CLI dump of the original stock factory supplied firmware? If you do, could you please possibly post it back here. My Phantom was bought almost 3 years ago and came with Betaflight 3.5.7 installed on it which has since been upgraded to 4.1 using iFly4rotor's factory CLI dump settings, but if yours is on an even newer 4.2 or 4.3 version of Betaflight it would be good to get hold of the factory dump for that later version too.

Yep, a new motor is far cheaper.. Any 1103 8000KV motor will do, right?

Mine is still on 4.1 IIRC (i'm at work) but i have a stock CLI backup:


  BTFL_cli_STOCK_PHANTOM_20220531_161612.txt (Size: 27.22 KB / Downloads: 31)

(20-Jun-2022, 10:11 AM)_Eend_ Wrote: Yep, a new motor is far cheaper.. Any 1103 8000KV motor will do, right?

Yes, you can get any motor of the same size / KV. Not all motors are identical (even from the same brand/type) but Betaflight will accommodate any differences between motors.

Thanks for the Betaflight dump. It's exactly the same as the one iFly4rotors posted so it looks like GEPRC are still shipping the Phantom with Betaflight 4.1.1 flashed to it's FC and with all the same settings as they were 2 years ago. I might eventually try mine on Betaflight 4.3 with one of the presets, but for the time being I will likely just keep it on Betaflight 4.1.