Tried tilt pot mod but burned something! Please help

[alecs]

Ok, I did something stupid today to my Phantom 2 radio (Phantom 1.1.1 that has the phantom 2 controller). I wanted to put the 5k potentiometer, soldered it apparently right without desoldering the original pot BUT... when first testing it I noticed the gimbal was barely moving when turning my 5k pot and at that point, completely forgetting about doing the pot calibration in the Naza assistant, I just started to swap the pot wires... and noticed smoke on my 5k pot. I obviously swapped the wrong wires and burned something, I hoped it was just the pots but I think something burned further in the board. Now I have no movements whatsoever on the x1 channel, unresponsive tilt command. All the other channels work correctly... now what could possibly fry? Call me stupid or whatever, but I really really didn't expect such a bad consequence. Is there something I can do, are there any available schematics on this board, the circuits are a pain to trace unfortunately... I think I've just ruined my weekend... and not only.

 

[syotr]

You have to remove the original pot. If you turn the new pot all the way in one direction and the original one is turned near the end of it's travel in the opposite direction, then you are effectively shorting out the whole circuit.
Try removing the original pot, replacing the new pot if it burned and then recalibrating.

 

[alecs]

OK, YOU CAN REALLY CALL ME STUPID! I figured out what I just did: I messed out with the wrong POT! Agter opening the case my brain got a little dissoriented and my eyes locked on the pot that sits below, the X2 pot... the mistery pot. Now the x2 pot is out, doesn't exist anymore as I messed too much with it and broke it. I did he right connections to the right pot and calibrated, now the gimbal tilt works as it should, thank God. Now, can I fly without the other pot in place? The Assistant says that X2 pot deals with s-bus control, IOC control, or remote gain tuning. The drone reacts correctly to my input, did the tinkering with X2 pot had any consequences?

 

[syotr]

You really should disconnect the original pot if you have not done so.

 

[alecs]

Ok, the pot is removed and my 5k pot is working ok. However, the mistery pot was also removed because it was damaged and I guess something did burn along the circuits for that pot and let me explain why:

- the first time I soldered my 5k pot on the mistery pot legs when turning the 5k pot the gimbal had a small movement and the radio started a continous beep when the limits of the pot were being reached. This led me to thing I soldered the wires incorrectly, which led me to reverse polarity on that pot, see some smoke and smell burned odor… after that the pot did not gave any answers at all and no more beeps so something did burn.
- finally I realised I have messed with the wrong pot and soldered my 5k pot in the correct place.

What did I do by turning the mistery pot around… burning it and eventualy removing it? Did I changed some gains, decrease tx signal power or changed frequency? Phantom seems to fly fine at this point but I'm not yet convinced is 100% ok.
Thanks. ,

 

[smallman28]

I know the pot you mean.
I wondered if it was something to do with the strength of the signal output?
On the Vision 2+ it performs that function but that runs on 5.8ghz

 

[alecs]

I'm afraid of that really... if it is indeed related to a signal output it's bad. Earlier today, on the second test flight I reached the max height limit set in Naza assistant (250m) and after a while the drone started to descend by itself rapidly, as if it lost signal and started return to home sequence.. .it started to respond to my full throttle input only after it had dropped for about 50 m. It's the first time this is happening, so if the mistery pot tunes the tx output what just happened to me is that I decreased the Tx range like a stupid... still, I need further testing to see if the range has suffered after today's unpleasant experience.

 

[lake_flyer]

Of course it is your call but if I were you I wouldn't test it myself. Send it to a DJI dealer and have him sort out what's damaged. Likely you need a new board or at most, a new radio. Cost won't be that high, after all a new radio unit is only around 110-120 bucks or so.

Imagine what could happen if your control signals are messed up somehow and you crash it onto a person or damage someones property. How would you determine if it's 100% safe? Even if it flies OK the next 20 times, it could still go totally nuts the 21st.

 

[Fyod]

The second pot is CE/FCC mode and only applies to Vision models (5.8GHz transmitter).
On the non-vision it doesn't do anything, although removing it may not be good. I don't know the original pot values, but these are parts that you can buy at any radio shack.
The beeps you mentioned mean low battery level. You may have shorted one of the batteries (which would be a small loss).

Replace all batteries
Fix FCC pot
Check function of the new gimbal pot
Test flight in secluded area

When doing any modifications to the Phantom or Tx, read instructions over and over and be sure about what you're doing.
If unsure, ask here.