Problem: Elevator and Rudder react together!

[Koarl]

Hey guys,

I have a problem and hope you can help me.

I soldered the connections for programming to the board and flashed the firmware. When I tested the TX it showed the following reaction:

when I do elevator or rudder, the two channels react together as if they were mixed, but they are´nt! I also tried the original FW but didn´t help. Also in the screen, where the channels activity is shown, the two channels go together.

Did I damage the PCB? Please help me.

Thanks

[Kilrah]

You probably have a short somewhere in the wiring of the 2 affected axes, or a blob of solder fell where it shouldn't... Check the potentiometer connections from the sticks all the way to the CPU and see if there's a short...

[Koarl]

I´m gonna try that, thanks!

[Koarl]

I had a look at the wiring. But didn´t find anything. Where exactly do I have to look?? Any hint? I´m not very good in electronics.

Thanks

[Crucial]

There's no telling where a solder ball could have lodged its self. Do you have a magnifying glass? You need to go over all the circuit boards and look at the different pins and connections. Also triple check the areas where you were soldering to make sure you didn't accidentally touch something with the iron.

[ShowMaster]

If you've selected a new model and it still happens check for a short between pins 60(elv) and 58 (rud). They should not measure as a direct connection. If that's OK trace those pins to the two SMD resistors and see if they have any bridged solder between them. You can also measure the pot center wiper connections to see if they are shorted to each other. Check and reseat the stick connectors going to elv and rud as well. Also look for any wires broken off the pots, maybe the ends?
Compare the other pot channels to the M64 pins to see what they read assuming they work correctly.
Check all the pot wipers against ground when centered and moved to both extremes. Somewhere in doing this you'll see a difference the M64 is swing and acting on hopefully. The difference will lead you to the fix.




ShowMaster
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[Koarl]

I removed the backside of the TX and unscrewed the PCB but on the first view I couldn´t find anything. But then it suddenly worked again. To be perfectly sure I tried again the next day and there was it again.

I´m gonna ask a friend of mine, who is far better in electronics than me. Thanks meanwhile for your support. I will let you know as soon as I figured out something.

Thanks!!

[ShowMaster]

Several guesses?
Some of the circuit board connections are on the ack side I think that has the black foam that presses against the LCD display. It's possible that some conductive "stuff" like solder splatter from assembly is trapped by the foam and loosening the screws released the pressure and it could return later. Maybe remove the foam and clean it and the board.
Another idea is as I mentioned, the connectors may not be seated and in removing them you did disturb those wires and connectors?
Have your technical friend trace pins 60 and 58 on the CPU to the stick pots and clean both sides of the board.
Report back if you find anything for sure please.


ShowMaster
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[Koarl]

Thanks, I will give that a try, when I´m back home. I will let you know, as far as I find something.

Thanks