Iris+ FS-TH9X Transmitter - stuck trim?

Hi Folks,

I just did the black light LCD mod and after putting the transmitter back together, I seem to have a stuck trim (right hand side).

When I switch on the transmitter, the 3DR logo appears, then the 'boot' beep happens, then the trim beep starts.  It starts slowly then speeds up.  If I press the UP button, the beeping ceases momentarily, then the LCD shows the trim gauge working up to the middle, then it shoots back down again and the beeping recommences.

I've taken the switch board out to make sure it's got nothing jammed under it, and it didn't.  

I know I've caused the problem.  It was working fine before I did the mod.  What I am hoping to find out is if there's a way I can either disable the trim, or fix it properly.  

Here's a video of the problem:

Thank you for any help, info, advice.


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  • That is really strange. My first inclination would be a jammed button or switch but you've indicated its been looked at already. While I don't have a solution I would like to suggest an additional resource for you.

    Join the Facebook group for Iris+ owners. It gets a ton more activity than this site and I'm sure you'll get a quicker response.

    Good luck.
    • Thanks, Andrew.  I have done as you suggested and joined the FB group.  I haven't had much luck with any suggestions though.  

      Living in hope I guess.  I think I'm resigned to getting another TX.  Not sure if I'll stick with the Iris one now though.

  • When I added the back light I lost all my telemetry. 3DR asked me to send them a video so I did not thinking that the back light was still in. So when they saw that all bets were off as far as warranty but they said that they would take a look at it so I sent it in. Now the Iris+ still flew fine but I sent it in any way. They forgot to tell me that if I need a new radio that they are out of stock. It took SIX weeks to get another radio. Check your plugs again and also broken solder joints. For the price we paid it really could have come with a better radio. Hope you find the problem and check there inventory before you send anything.


    • Thanks, Keith.  That certainly a horror story.  When you got it back, was it all OK?

      I've checked, double checked and triple checked the connections and can't for the life of me work out what is wrong.  Short of having an issue with the CPU, I can't see a physical issue anywhere. 

      Thanks for the reply.


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