Help! Rx/Tx misbehaving - Motors and servos jittering automatically without any input from TX

[theweblover007]

Update: Now the tx and rx have completely stopped working

. TX powers on like usual but not the RX. As soon as i plug in the esc to rx, red light turns on for a fraction of a second and goes away. I tried to add a jumper between ground and signal on the reciever and now the red led on rx starts blinking (like it should do when a bind plug is inserted). However, i am not able to bind the rx to tx anymore.

Hello Everyone,
I am facing an issue since yesterday, When i turn my TX and RX on, the motor as well as servos on my plane start going off/jittering (See video)
Note that i resoldered my antenna to the receiver about a week or two back (didn't have problems before yesterday).
Problem goes off after i turn off my TX.

Please checkout the video showing this problem here : https://www.reddit.com/link/iv9jsb/video/lu71cqb0pxn51/player
Image after my soldering work :




I would appreciate any help regarding this. Sorry for the large images.
Thank You

 

[JasonK]

Problem goes off after i turn off my TX.

I see 4 possible issues here:

• your TX is so close to the RX, that your inducing unexpected noise into the RX
• Something bad has happened with your re soldering attempt and the RX is bad (IE it is gaining/loosing the signal repetitively and the TX center and the RX no signal posions are different)
• your TX is bad and sending bad signals

the best way to pin down if it is an issue with your TX or RX, would be to test with a different RX.
IIRC those RXes can be configured via the TX for how loss of signal is handled, I am curous if it is set to no pulses on LOS or to go to some set positions.

 

[JasonK]

FWIW: that board looks burned and likely damaged by your soldering attempt

 

[Merv]

What is the blinking orange light on your Tx? Was the antenna connected to the Rx during the video?

I agree with @JasonK, your Rx and/or Tx may be damaged.

 

[theweblover007]

FWIW: that board looks burned and likely damaged by your soldering attempt

It was just the flux gunk actually, Here's the updated photograph after cleanup :

 

[theweblover007]

What is the blinking orange light on your Tx? Was the antenna connected to the Rx during the video?

I agree with @JasonK, your Rx and/or Tx may be damaged.

Yes, it always blinked like this. As soon as i turn the tx off, the jittering stops therefore the remote is connected to rx.

 

[theweblover007]

I see 4 possible issues here:

• your TX is so close to the RX, that your inducing unexpected noise into the RX
• Something bad has happened with your re soldering attempt and the RX is bad (IE it is gaining/loosing the signal repetitively and the TX center and the RX no signal posions are different)
• your TX is bad and sending bad signals

the best way to pin down if it is an issue with your TX or RX, would be to test with a different RX.
IIRC those RXes can be configured via the TX for how loss of signal is handled, I am curous if it is set to no pulses on LOS or to go to some set positions.

The problem still occurs when TX is far from RX. Can you please elaborate a bit on the "the TX center and the RX no signal posions are different". After i attempted soldering, it still worked for a week.

Also, I did not make any changes to TX so i'm not sure how it can go bad. Can i run some diagnostics ?

 

[JasonK]

Can i run some diagnostics ?

yes, get a second receiver and see if the issue happens with the second receiver also or just this one. if the issue persists, you have a bad TX, if the goes a way with a new (known good) receiver, then the issue is your receiver.

 

[JasonK]

It was just the flux gunk actually, Here's the updated photograph after cleanup :

I have marked here the locations were I see what looks like some possible solder bridges and other bad/questionable looking solder joins.

 

[Merv]

As soon as i turn the tx off, the jittering stops therefore the remote is connected to rx.

Im not sure I can agree with your statement. Jittering does not equal a connection, control equals a connection.

The lack of an antenna may be your problem.

 

[JasonK]

looks like you have a Flysky system, what is the link quality reported on the TX when connected to the RX?

 

[FrankFly]

Have you tried re-binding the receiver to transmitter? I had something similar and it was as simple as that.

 

[sprzout]

Are you using an ESC with a BEC? How many amps is your BEC? I had something similar with an ESC that only had 2 amps. I had 6 servos connected, and it started fluttering with the servos - it couldn't handle the amp draw. Switched out to an ESC with 3 amps, and the problem went away.

 

[theweblover007]

Update: Now the tx and rx have completely stopped working

TX powers on like usual but not the RX. As soon as i plug in the esc to rx, red light turns on for a fraction of a second and goes away. I tried to add a jumper between ground and signal on the reciever and now the red led on rx starts blinking (like it should do when a bind plug is inserted). However, i am not able to bind the rx to tx anymore.

 

[theweblover007]

Are you using an ESC with a BEC? How many amps is your BEC? I had something similar with an ESC that only had 2 amps. I had 6 servos connected, and it started fluttering with the servos - it couldn't handle the amp draw. Switched out to an ESC with 3 amps, and the problem went away.

But my ESC was working totally fine a few days back. Please see the update, i tried using external 5v supply (breadboard power supply) and yet no luck

 

[theweblover007]

I have marked here the locations were I see what looks like some possible solder bridges and other bad/questionable looking solder joins.

Thanks for you reply. I checked those joints again but there is no solder bridge there (doubled checked for continuity using multimeter). Its probably a reflection from my phone flash that looks like a bridge. Also, please see the updated situation.

Thanks again!

 

[sprzout]

Update: Now the tx and rx have completely stopped working

TX powers on like usual but not the RX. As soon as i plug in the esc to rx, red light turns on for a fraction of a second and goes away. I tried to add a jumper between ground and signal on the reciever and now the red led on rx starts blinking (like it should do when a bind plug is inserted). However, i am not able to bind the rx to tx anymore.

Do you have another receiver or another plane that the TX works with? If so, it's not the TX - I'd look at trying to swap out the RX.

 

[Merv]

However, i am not able to bind the rx to tx anymore.

Sounds like your Rx is bad. When an Rx starts to go bad, it can do unpredictable things. I've seen people try to use a questionable Rx, they may one to work, only to crash the plane when the it fails mid flight.

 

[theweblover007]

Do you have another receiver or another plane that the TX works with? If so, it's not the TX - I'd look at trying to swap out the RX.

Sounds like your Rx is bad. When an Rx starts to go bad, it can do unpredictable things. I've seen people try to use a questionable Rx, they may one to work, only to crash the plane when the it fails mid flight.

Thanks guys for the help. I'm ordering a FS CT6B since my current tx is a chinese close of it. Lets see if I can figure out the problem.

Thanks

 

[FlyerInStyle]

Thanks guys for the help. I'm ordering a FS CT6B since my current tx is a chinese close of it. Lets see if I can figure out the problem.

Thanks

also, try sttingg your trim neutral, and making sure that the servos are in their original nuetral position. I had the same problem with the same servos I believe when I programmed my flaps to go too low, and it was too much foor the servos.