I am trying to re-setup my quad that I left for almost 4 years, it was flying before without any issue and that time I quit this hobby due to personal reason.

Now, after come-back I wanted to change old TX settings & FC firmware update so, I reset all settings for transmitter & SP F3 flight controller without any backup ( obviously i didn't expect this issue will happen). And I followed all necessary steps for setup.

After connecting to the configurator Receiver tab, I see the channel values are jumping randomly. when I turn off transmitter all channel goes to normal values & locks up.



I tried many things to solve this issue by - Downgrade FC firmware, switched from cleanflight to betaflight, chnaging IO cables, checking channel connection from RX to FC, tried Binding procedure, recalibrating sticks, changing TX batteries and also I turned off TX mix, Dual rate settings but it didn't help.

I saw one thread that is looking similar to my problem but I didn't get any idea, please visit it may become helpful to reach at conclusion - https://intofpv.com/t-puzzling-receiver-problem

Can you post a photo of the wiring? And a dump file. Make sure you don't have something else soldered to the same port.

(09-Jun-2021, 07:43 PM)voodoo614 Wrote: Can you post a photo of the wiring? And a dump file. Make sure you don't have something else soldered to the same port.

It is PWM connection & I connected it same as in uploaded picture. VBAT, Buzzer & all UART ports are not in use. And I removed FPV system also.

I noticed when I turn on transmitter, red LED on FC didn't goes solid & still continue blinking. is it normal ??

That is very interesting. Do you have a servo tester to see if the problem is the FC or radio/receiver?

(10-Jun-2021, 06:09 AM)voodoo614 Wrote: That is very interesting. Do you have a servo tester to see if the problem is the FC or radio/receiver?

I have this one, will it work ? What I have to do , please tell me

It should work. Wire the PWN signal from tester to one of the channel input on the FC. See if you get a stable PWM registering in the receiver tab.

(10-Jun-2021, 06:26 PM)voodoo614 Wrote: It should work. Wire the PWN signal from tester to one of the channel input on the FC. See if you get a stable PWM registering in the receiver tab.

I connected servo 1 connection to throttle channel input on the FC, then I heard motor arming sound &  I checked in Receiver tab, there is no movement of any channel even I tried to command FC input channel by servo knob(throttle). Also aux channel were showing unavailable.{image 1 & 2}

Then I connected RX output(channel 3, i.e throttle) to ESE connection again I hear arming sound & motor started spinning randomly. I checked the TX display but all values are stable, I think channel values were jumping as described earlier thats why motor was spinning randomly.{image 3}

You can try to connect the ESC directly to one of the radio (eg. Throttle ch) and you should be able to spin the motor. If you can spin the motor smooth with this direct connection, then you can safely say something is wrong with the FC.

(11-Jun-2021, 06:00 AM)voodoo614 Wrote: You can try to connect the ESC directly to one of the radio (eg. Throttle ch) and you should be able to spin the motor. If you can spin the motor smooth with this direct connection, then you can safely say something is wrong with the FC.

Yes, I tried it & motor started randomly spining & stopping without my stick command, it is happening due to sudden jump on channel value. When I pushed throttle stick up it started spining continuously , but due to fluctuations on channel spinning was not smooth.

I see. So maybe the receiver is acting weird.

(11-Jun-2021, 06:26 AM)voodoo614 Wrote: I see. So maybe the receiver is acting weird.

What should I do ? Do you have any solution ? One more thing, I replaced TX battery with li-ion 3.7v 18650 3cell,that I made. Do you think this can cause any problem to TX ?

The radio is rated for 12V. So 3S is should be fine.

No solid solution. My advice, probably a time to upgrade to modern day transmitter and receiver.

(11-Jun-2021, 10:17 AM)voodoo614 Wrote: The radio is rated for 12V. So 3S is should be fine.

No solid solution. My advice, probably a time to upgrade to modern day transmitter and receiver.

Government have banned Drone & import of 2.4ghz transmitter. I ordered frysky taranis Q X7 on 2017, that was held by custom office (situated on another state) & I couldn't go to report because I was busy at my university exam. I don't know whether they returned the parcel or destroyed it, Due to this I lost 100$. Thats why I still rely on PWM transmitter.

And here I am the States, I thought the regulations are bad. I feel for you.

Are you able to import the 5.8gz stuff?