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Jun 14, 2014, 05:04 AM
Flying a Chipmunk in Portugal
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9XR-PRO Hacks and Fixes

Following the idea of a RCG user I decided to create a thread where we can discuss and share mods you do to your radio, as well as problems you may encounter and how you've fixed them.
Please keep it friendly as we are all good people
Thank you..


EDIT: I've created a similar thread also at
Last edited by jhsa; Jun 14, 2014 at 05:10 AM.
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Jul 08, 2014, 01:44 PM
Registered User
Rotary Encoder :
Digi key # 987-1188

4 pin JST PH series connector shell

crimp on wire terminals (4 needed)

Sample Knob :
1/2 " Dia. 3/4" Long 1/4" "D" style shaft

I will make a wiring diagram asap.

Last edited by SkyNorth; Jul 09, 2014 at 04:57 PM. Reason: additions
Sep 02, 2014, 12:40 AM
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9XR Pro Multi-Port Housing Mod

There is an issue with the Multi-Port used in the Turnigy 9XR Pro, which I discovered when removing the main board to inspect my LCD.

The original 9XR had the Multi-Port housing made so that it pulls straight up away from the board for removal, allowing access to a screw underneath. The way my Pro is made the plastic molding traps the assembly under the power jack, and blocks access to one of the screw holes underneath. In the case of my TX, they omitted said screw in manufacture. I do not feel that 3 screws is adequate to retain the mainboard properly; the [EXIT] button is not firm as a result.

One has to remove the audio jack and disassemble the housing to remove it from the mainboard as it is; clearly this is not feasible with the board in the TX.

I've modded the Multi-Port Housing on my 9XR Pro to address this issue; details are shown below:

Once completed, the Multi-Port assembly will easily slide around the power jack and pull straight up off the board while assembled in the TX. This makes for easy access to that 4th screw.

Hope this helps a few folks get this issue sorted,

*At some unfixed point*
Last edited by mnemennth; Sep 02, 2014 at 10:59 AM.
Sep 02, 2014, 12:41 AM
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9XR Pro Dim LCD Backlight Fix

After receiving my shiny new 9XR Pro and having some time to fiddle around with it, I found myself struck my how dim the LCD seemed; at first, I simply assumed it had the brightness turned down by default. Once I found the brightness control in the menu, I was very disappointed to find it was in fact at 100%.

Side-by-side comparison* with my other Turnigy TX showed I wasn't mistaken; even my venerable old 9X was brighter, and the Pro was no where even CLOSE to the same crisp, bright display that was one of my favorite things about the 9XR.
*I know it's hard to see in this photo; but in real life, the difference is HUGE. This photo is the best of dozens I took trying to document the issue; evidently it is just one of those things that's very hard to photograph.

Questioning Mike & Brent revealed that the Pro uses the same LCD and Backlight array as current 9XR production; so clearly something else had to be at fault. A little poking around with my multimeter yielded an answer; there was something awry in the design of the LED Backlight power circuit.

Location of R56 and Q3 - Backlight Control Circuit

The 9XR takes power direct from 12.6V battery voltage at the power switch; it drives the LCD backlight array at 55ma total through a 150Ω ballast resistor. It has 5 LEDs in parallel; dividing that current by 5 yields 11ma per LED.

The 9XR Pro takes it's power from the main 5V switching regulator; it drives the entire array at 11ma. 11ma/5 LEDs in parallel = 2.2ma per LED. THIS is the cause of the relatively dim LCD backlight. Due to some clerical error, there was a 200Ω ballast resistor used at R56 for the LCD Backlight; with the circuit taking power from a 5V source this value is REALLY off; it should be considerably LOWER resistance than the 9XR, not higher.

Doing some calculations for this panel using a 5V source with a typical 3.4V Forward Voltage for the LED, we come up with:

5V - 3.4V VF = 1.6V/0.055A =29.1Ω with a resistor PD of 0.09W. Closest standard resistor will be 33Ω 1/8W.

Based on this, I've done some real-world testing by replacing R56 in my with some standard resistors. Testing with my multimeter yields the following:

At 100% a 33Ω resistor yields 52.5ma total draw @ 2.94VF; this is 10.48ma/each LED. Calculated PD with 1.868 V dropped across R56 is 0.106W. This is pretty nominal compared to the 9XR, and appearance wise, it is so close to the same brightness that I can't tell the difference between the two.

At 100% a 22Ω resistor yields 67.4ma total draw @ 2.998VF; this is 13.48ma/each LED. Calculated PD with 1.625 V dropped across R56 is 0.121W. This is still well within typical max ratings of 20-25ma for these little SMD LEDs, and it is quite a bit brighter (and lighter shade of blue) than the stock 9XR; I have to turn it down to 75% to get the same perceived brightness. I LIKE it; I'm gonna keep it and report on how it holds up over the long run.

1206 Size Resistor vs 0805 Size Comparison

Calculated PD says we should be able to use a 1/8W 0805 size SMD resistor, but it'll be right at the limits of its rating. However, due to a lucky fluke in the layout of the board, we can actually fit a 1206 size 1/4W resistor in there by soldering one end of it to the solder pad at the collector of Q3 and not have to make any modifications to the mainboard at all.

Alternately, one can use two 68Ω 0805 1/8W resistors stacked one on top of the other to get 34Ω; this will fit on the original R56 solder pads.

9XR Pro with 22Ω 1206 Size 1/4W Resistor at R56

TL : DR Version:

My recommendation to those playing along at home would be to replace R56 with a 33Ω, 1206 size 1/4W resistor; this results in almost identical current draw and brightness to the tried and true original 9XR design, so should be similarly reliable. If you want to experiment with a brighter display, try a 27Ω or 22Ω 1206 size 1/4W resistor; that's what I'm using.

With this issue resolved, I'm loving my Pro again!

As always, thanks to Mike & Brent for bringing us this awesome TX; and especially for their assistance with technical specs while I wrangled with this issue!

*Feeling Brighter*
Last edited by mnemennth; Sep 02, 2014 at 11:00 AM.
Sep 02, 2014, 12:44 AM
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9XR Pro Speaker Mod

Like the Taranis, the speaker on the 9XR Pro is somewhat anemic. This can be blamed on both the fact of using a small Mylar pancake speaker, and the fact of trying to use said speaker in "free-air" mode with no soundbox in front and no resonating chamber behind the diaphragm.

I'm working on a couple of Mods; this is my first one:

This Mod is to build a sealed soundbox. I cut a 15mm wide strip of plastic from a Drink Mix box like so.

Trim it to fit against the upper bulkhead of the TX and cut a notch out for the back of the [READY!] LED indicator, then commit some Hot Glue Abuse to seal it all in place. Also, remove the brace on the upper bulkhead for room for the speaker.

Here I'm fitting my 40mm replacement speaker; you can use the original 36mm speaker the same way.

A little reality check to make sure it will actually fit under the Trainer Port bracketry...

...and more hot glue abuse to seal it in place. I tried this with both speakers sealed up this way; the stock speaker is about twice as loud and much clearer than before. The 40mm 8Ω 0.25W speaker is a little louder than the stock one, and the overall tone is better operating without a resonating chamber so I went with it. But for ZERO DOLLARS out of pocket, just doing this mod with the stock speaker is a HUGE improvement.

Volume is now about 2.5x that of the stock arrangement. However, both speakers still sound "tinny"; this is a fact of life with Mylar speakers. I want better tonal quality, so next I'm going to try a 40mm x 28mm 4Ω speaker from this auction.

I expect to be able to build a small resonating chamber around it thanks to being able to set it lower inside the space; that should help greatly with overall sound quality. I'll update here once parts arrive.


Sep 02, 2014, 12:45 AM
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9XR Pro DIP Switch Mod

So now you've got your shiny new 9XR or 9XR Pro, and you want to start adding goodies. Maybe a Bluetooth module, maybe you need to switch some inputs to something else, maybe you want to add a light or buzzer or thingamabob. But you need to be able to turn it on and off. Jumpers are too much hassle, but you don't really need to dedicate a switch on the front panel to it; what to do?

This is a great job for an 8-position DIP switch in the Battery compartment. Common DIP Switches can carry current up to 500-1000mA ; this makes them great for enabling small loads and redirecting signals. A reminder: It is best to make sure you do NOT switch them under load; always change DIP Switches with the Radio OFF.

You will need:

1) 8-Position DIP Switch, "Piano-Style"

1) 16-Pin DIP Socket

2) Pieces of 3/16" (4.8mm) Square Plastruct 3/4 inches long; glued side x side to make spacer

1) Sharp X-Acto Knife and/or a Dremel tool


CA & Accelerant (Recommended but not absolutely necessary)

"NO FEAR!" Attitude towards sawing and cutting on the insides of your 9XR or 9XR Pro.

First, remove the back of your TX.

If you're not afraid to, remove the RF board and the speaker and the bracket it sits on. If you're planning to do a speaker Mod like the one I posted previously, now's a good time to get it all done at once. This job CAN be done with the bracket in the TX; it just means you need to be extra careful of the face of the TX because you are going to be sawing and cutting pretty hard. And making a big mess inside your TX that will need to be sucked out with a vacuum hose.

First, cut out the area of the RF board bracket like so between the battery connector and the empty slot with a filler plate in it. DON'T cut away the material that supports the Battery Connector and Filler Plate. The highlighted area includes material I cut away before taking the picture; silly me.

Here is an overview of what we're making, and the unmolested RF Board bracket in my 9XR for comparison so you can see what needs to be cut.

Assemble the DIP SWitch into the socket, then bend the pins of the DIP Socket up around the outside as seen on both sides so the DIP Socket can lay on top of the spacer as shown.

Glue your two pieces of 3/16" Plastruct together as seen in the Epoxy Mixing tips photo below. 3/16" / 4.8mm thick is important; 1/4" thick will raise the assembly too high and a standard DIP Switch will interfere with closing the battery cover.

Mock up with the spacer made out of Plastruct and make sure you've removed enough material that you can align your DIP switch and spacer as shown.

Mix up a batch of epoxy approx the size of a nickel or quarter. I recommend gluing the Plastruct together beforehand with CA as seen here so it's one piece; but you CAN just work with them loose as you will be epoxying both top & bottom in place.
Epoxy the spacer to the RF Board bracket, then epoxy the DIP Socket with switch on top of that. You will be embedding a small portion of the pins of the DIP socket in the epoxy on top of the spacer; make sure not to cover the entire pin with epoxy or it will be very nasty-smoky when you go to solder your wires to the pins.

Make sure you have the DIP switch aligned precisely as you mocked it up previously, then allow to cure. Here's that picture again, just to prevent any confusion. You need to get this right on; once it's in place you'll have approximately 1/8" (2-3mm) space behind the switch to route all your wires to the back pins.

Here's what the back of the DIP Switch will look like when it's located properly. Note pins bent up around the DIP Socket here as well. Each pair of pins, front and back, corresponds to one switch. Dead-simple.

Before you solder ANYTHING to the pins of the DIP Socket, unplug the DIP Switch by rocking one end slightly loose, then the other with a knife as seen here. The heat from hand-soldering can damage the switches internally, making contact intermittent. Do NOT attempt to pull it out by hand; the pins are typically made of hardened brass spring stock and you'll bend them, then when you go to straighten them they break off.

Now you are ready to wire it up to your favorite gadget! Excellent!

Now go get your Dilbert on!

Wyld Stallyns RULE!
Last edited by mnemennth; Sep 02, 2014 at 10:04 AM.
Sep 02, 2014, 12:50 AM
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Turnigy 9XR / 9XR Pro White LED Backlight Mod

The name pretty much covers it; if you want to change the color of your 9XR/9XR Pro's LCD backlight, then you're in the right place.

You will need:

5) 3020 size BRIGHT WHITE LEDs, 3500mCD or higher

1) 1206 size 22Ω SMD Resistor (Or 2 0805 size resistors totaling 17-22Ω in series or parallel)

A decent, temperature-controlled soldering station with a 0.1mm fine tip

Very fine solder (I prefer Radio Shack # 64-035 0.015" Silver-Bearing Solder for this type of delicate work)

Fine-braid Solder-Wick or equivalent desoldering braid

An X-Acto Knife with a halfway decent # 11 blade

Some patience and a little technical ability.

First, we need to get some new LEDs. The ones I used came from this vendor:

No ePacket shipping, so they arrived in about 12-13 days.

Your other option is to go to eBay, type "3020 White LED" in the Search box and wade through the 7-10 pages of hits, looking for the one or five listings that AREN'T some sort of idiotic mood lighting for that kid with the saggy pants to put in his Hoopty.

If you want another color besides the ones in that listing, I'm afraid you're going to have to brave that tidal wave anyways. Sorry.

Don't bother with the "Purple" ones; most of their emission is in the UV range. Unless you want to see that mustard stain on your shirt glow in the dark, they're useless as backlights.

Remember that different color LEDs have different Forward Voltage; this means you'll need to calculate different values for R56. You are calculating for a MAX forward current of 55-70mA total with a source voltage of 5V; that drives these LEDs at 11-14mA each. This leaves a little wiggle room for variations in the current draw of individual LEDs.

You can use the LED calculator here to help you:

Remember that the 9XR uses a source Voltage of 12.6V, while the 9XR Pro uses 5V. Treat the entire array as a single LED needing 55-80mA of current to drive it.

Plug in the Forward Voltage of the LEDs you are buying. Remember that the calculator will choose the next higher resistance standard value resistor; if that doesn't produce enough current, move to the next lower value and try again.

As a comparison, I'm driving Red LEDs in a similar array with a 33Ω ballast resistor at 5V, as well as Aqua Green and Blue ones with 22Ω resistors. These values produce very conservative current draws in the ranges shown above. Orange, Amber, Yellow and Pure Green LEDs will typically have forward voltages similar to the Red LEDs used above, so will probably need closer to the 33Ω ballast.

$5.00 got me 50 pieces with shipping. These LEDs are pretty awesome; you'll find a use for the rest of 'em.

For the sake of progress, we'll assume you're capable of removing the backlight without destroying your radio. If you aren't, ummm... sorry. This isn't a job for the timid or the completely non-tech-inclined.

The backlight has a translucent side, and a nearly-opaque white side. The white side is the back.

The back is held on with two thin strips of double-faced tape. Using the edge of a paring knife, start lifting the white plastic sheet at one of the corners on the edge with the LED strip. Be VERY CAREFUL handling the backlight so as not to scratch the front side; it is possible to scar it badly enough that you can see it through the LCD.

Continue peeling back the white sheet ...

...and now the LED strip can be seen.

On my 9XR, the LED strip just slid into this slot at each end of the backlight lens. On my 9XR Pro, they had CA (Superglue) to hold it in place. By repeatedly gently pulling the LED strip away from, then pressing it back down on the lens at about 3/4" (20mm) from each end, you can break the CA loose, then slide the LED strip free.

And here's the LED strip out of the lens. Note that polarity is marked at each LED. Maybe they were expecting us...

By applying heat with the tip of a soldering iron, you can slip the tip onf an X-Acto knife under the solder joint; lift up just enough to separate the solder from the LED. Repeat on the other side and the LED will fall off.

Touch up the pads with a little desoldering braid to get them ready.

Now it's pretty simple; just hold the LEDs in place and tack the solder tabs to the pads on the LED strip. Note that the notch denotes Cathode (-) tab on LED.

Once you have them all tacked down, go back over with a cleaned iron tip and fresh solder, making sure the LEDs are all straight.

While you have everything apart, I suggest unsoldering the leads from the LED strip and adding a little heat shrink tubing...

... you'll need to put a little "pre-curve" into the leads & heat-shrink while it's still hot so everything still plugs in as it should.

If you're working on a 9XR the OEM ballast resistor is pretty close to nominal value already, as the LEDs are driven from full battery voltage. It drives these LEDs at 55mA total, or approx 11mA each. You can move onto reassembling your backlight and testing.

If you have a 9XR Pro, there's a little extra work you'll need to do...

These LEDs have a slightly higher Forward Voltage than the original Blue LEDs; if you haven't already done my "9XR Pro Dim LED Backlight Mod", you'll need to now.

On the stock 200Ω ballast resistor at R56, these will barely light up at all. You'll need 17-22Ω at 1/4W to bring these up to full brightness at 65-80ma for the total array. The closer to 17Ω you get, the brighter Max brightness will be.

Bridge both ends of R56 with a blob of solder and just wipe it off the pads with the tip of your iron.

Here's a comparison between the original 1/8W 0805 size resistor and a 1/4W 1206 size 33Ω resistor. As you can see, the 1206 size resistor will fit if we solder one end of it to the pad at the top of Q3. PD here is right on the edge of 1/8W so we really need to have 1/4W of ballast resistor; hence the bump up to 1206 size.

I later switched over to the 22Ω resistor seen here for my OEM Blue Backlight; it drives that at about 14ma per LED. It drives these at 10-11ma each; right about the same brightness as the original 9XR backlight.

I subbed a 17Ω resistor for testing here and it drove these at approx 14mA each; the backlight looks a little less grey and noticeably brighter.

Time to test! Dang those are bright!

But after running over 30 minutes, still room temperature. Excellent! Time to reassemble everything!

Here's some screen shots of the new brighter, whiter LCD! w00t!

With the White LEDs, the LCD looks a bit better with Contrast cranked up to 25; Other colors will look better at different contrast settings.

Well, that pretty much covers it. Now you know how to put pretty much any color LED you want in the backlight of your 9XR/9XR Pro!

Good Luck!

Keep Moving Forward.
Last edited by mnemennth; Sep 02, 2014 at 09:26 PM.
Sep 02, 2014, 09:26 PM
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Joćo -

I know I promised you this content here a while ago... been a bit busy hacking, not enough time documenting. More to follow, I promise!

*Used up*
Sep 03, 2014, 05:00 AM
Flying a Chipmunk in Portugal
jhsa's Avatar
Thread OP
No problem.. everybody should post their hacks here and on the other forum.. I'm sure there are different ways of doing the same thing and it would be interesting to see what different people do to hack/fix their radios
Sep 08, 2014, 11:13 PM
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Turnigy 9XR / 9XR Pro RGB LED Backlight Mod - Transmitter BLING!

Turnigy 9XR / 9XR Pro RGB LED Backlight Mod - Transmitter BLING! (4 min 35 sec)

Custom RGB LED Backlight assembly replaces OEM; controlled by RGB LED Strip lighting controller.

TX Has both LCD Backlight and [READY!] LED converted so overall "look" is complete; IR remote controls Color selection and Brightness, but controller is integrated so that software is still able to switch backlight ON & OFF as usual.

Controller has 15 pre-programmed colors plus White; it also offers four cyclic lighting effects to complete the "Bling!"

I am currently in the process of writing up a photo how-to in my Blog; I will update here when it is completed.

And yes, I will soon be working on a version for the Taranis/Taranis Plus!!!

Thanks for viewing,

Last edited by mnemennth; Sep 08, 2014 at 11:46 PM.
Sep 09, 2014, 06:25 AM
65 years of RC flying
Daedalus66's Avatar
Great stuff! Thank you.
Sep 19, 2014, 05:52 AM
Flying a Chipmunk in Portugal
jhsa's Avatar
Thread OP
Yeah, definitely great stuff.. Now if we could replace the original LEDs ewith RGB ones but control them with the radio firmware, it would be a killer.. Don't know if Mike follows this thread though..
May 30, 2015, 10:01 PM
Registered User
Can the FRSky XJT module be modified for telemetry with the 9XR Pro the same as the DJT module?
Sep 12, 2015, 07:54 AM
Registered User
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Originally Posted by SkyNorth
Rotary Encoder :
Digi key # 987-1188

4 pin JST PH series connector shell

crimp on wire terminals (4 needed)

Sample Knob :
1/2 " Dia. 3/4" Long 1/4" "D" style shaft

I will make a wiring diagram asap.

Ok now that I found the rotary encoder, what is this going to do act as a 6 position switch? when you install it will the software find it, are will you need to tell the software its there?

I'm am at a lose
Sep 14, 2015, 06:43 AM
Registered User
The rotary encoder is not the same as a 6 pos swtich.
It continuously rotates , it has no stops is used for menu navigation, and
as a variable input.

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