Turnigy 9x help

[carmojos]

Hello all,

I bought a used turnigy 9x on eBay and am attempting to repair it. I am new to the hobby and building my first plane now. Now onto the transmitter.

Whit the stock firmware the unit never beeps or even boots. I added a programmer and installed er9x. That firmware bots, but when I attempt to turn the volume on the system crashes and then will not boot. I have some experience in electronics and have the equipment to fix it.

When I received the transmitter I had to replace the 78L05 before the system would even run. I can bind the system, but it does not appear to ever transmit.

Any suggestions on where to looks for the problem?

 

[joshuabardwell]

So you were able to successfully program the chip, right? When you plugged in the programmer, did the unit power up? Did the display come on?

You say the firmware boots but crashes when you try to turn the volume on. So does the controller work fine when the sound is off?

Have you tried de-soldering the speaker connection from the board? Maybe there is a short in the speaker connection that is causing a brown-out when the unit tries to play sound.

 

[carmojos]

No. The unit does not work with the sound off. Er9x does power with the programmer plugged in. The default does not.

The speaker connections appear fine and the speaker work if I drive it with 5 volts disconnected.

I can flash the chip and the display does come on. With the system powered from the programmer I can set the volume in er9x to any setting, but running off the battery I can only get to xShort before the system restarts.

I am able to bind to a receiver, but I can not control a servo.

I have had to replace 2 of the three 7805 regulators. At this point I an thinking the 8050s needs replaced, but can not find a source.

 

[joshuabardwell]

I don't have any more suggestions for you, sorry. I agree that something on the board is fried, but I couldn't say what it might be. The microcontroller seems to be working, so it must be some supporting hardware, probably related to the power system.

When I plug in my programmer, the system takes power from the USB, through the programmer, not the battery. I have never tried to use the transmitter in that state, but I wonder if it would work for you. The min voltage for the 9x is 7 volts, but that relates to the voltage regulator. The system actually runs at 5v, I think, I would think you could control servos when powered off of USB. This would confirm 100% that the issue is something in the power circuitry.

If you have a 5v bench supply, you could also try putting power directly onto Vcc and Gnd somewhere they are accessible.