Throttle Warning

[mpjf01]

I was asked to help a friend this afternoon. He has a standard 9x with a Smartieparts board. He installed a switch to enable RF output to be switched between an internal DIY module and a yet to be tried/installed Orange plug in module. He is switching the 5v feed and the ppm signal.

After making the mods he switched on the radio and the firmware/eeprom load seemed to freeze with a model name on the screen. The TX was unresponsive. He asked for my help, all I could think of to do was to reload the firmware and a known working eeprom. We did this with a fresh firmware download, no options, and one of my functional eprom files.

The firmware and eeprom loading is successful and is able to be loaded back with C9x, so that part seems to be working Ok. The Tx screen shows the normal bad eeprom message after the firmware loads but after loading the eeprom there is a throttle warning, press any key, but the Tx is unresponsive.

Something he did when installing the module selection switch seems to have broken the eeprom loading. Can anyone suggest what to look at next please?

[jhsa]

Well, the throttle warning could be because you uploaded your eeprom with your calibration values.. I think if you calibrate the sticks the warning will go away.. But I'm not sure if you are able to do that as you say the tx is unresponsive.

Idea, might not be the case, but can you READ the fuses with companion? Note that I said read.. don't write anything at this stage.. specially not the fuses

Go to "Burn menu>Fuses>read fuses"
Please post the fuses values here.

João

EDIT:

He is switching the 5v feed and the ppm signal.

Hmm, just read your post again..
I think the modules get Battery voltage, not 5V..
More details how he did the mod please. he should be switching battery voltage, not 5V

[mpjf01]

Thanks Ill check with him. I didn't check myself where the power came from. Just a red wire on the back board.

Sent from my GT-I9100 using Tapatalk 2

[pmullen503]

The 9x module bay has no 6v pin. On mine, pins 2 and 4 are ground. Pin 3 is Vbat. It's NOT a standard JR pinout.

[mpjf01]

He's cut the + and ppm tracks that go to the plug in module pins on the back board and inserted the 2 way switch with take-offs for the DIY and returns from the switch to the module pins where the tracks go when uncut. The DIY module is powered (with the appropriate switch selection) but don't know whether or not it is fully functional. The ground track was not cut and is not switched and the DIY ground comes from the back side of the module pin as is usual.

At the start of the firmware loading process I had the setting that automatically backups and restores the eeprom set. When the new firmware loaded with the reloaded original eeprom I didn't get the throttle idle warning, instead switch warnings which would not go away and the Tx was locked. The throttle warning came with a later load of my eeprom. I assumed that both were symptomatic of the same problem.

[Kilrah]

Do the warnings go away when pressing a key?

[mpjf01]

No the Tx is completely unresponsive.

[Kilrah]

You may want to try flashing the key diag version of ER9X to see if the keys are working. Some have already had issues with that...
With a blank eeprom it's not possible to pass the throttle warning with uncalibrated sticks, so if the keys are unresponsive you can't go anywhere.

[mpjf01]

Thanks, hopefully I'll see him tomorrow and we will try that. I am concerned though that the Tx was locked up when I first saw it (with the active model name only displayed) and also when I first flashed it with the latest OpenTX and restored the previous eeprom (with a switch error, ie it got past any throttle warning). In no case have the keys done anything.

[MikeB]

Check the trim switch signals. I believe that if a trim is stuck active, it will block the use of the other buttons.

Mike.

[mpjf01]

You may want to try flashing the key diag version of ER9X to see if the keys are working. Some have already had issues with that...
With a blank eeprom it's not possible to pass the throttle warning with uncalibrated sticks, so if the keys are unresponsive you can't go anywhere.

I have now got hold of the radio and replaced the main board with one of my own as a test. The radio works fine, suggesting that the problem might be in the board.

I loaded the key diag version of ER9X as suggested using the (assumed) faulty board. On startup I get the message "Throttle not Idle Press any Key....' but key pressing does nothing and the message remains. It occurred to me that one of the press buttons on the main board could be stuck on, so I tested each one with a meter. There was zero resistance in the Menu button whether pressed or not so I removed the button with the intent of replacing it as I assumed it was faulty. With the button removed the resistance across the points where the switch had been was still zero so the issue was not with the switch. One side of the switch is connected to processor pin 11 via resistor. I'm not sure what the other side is connected to, but presumably there should not be continuity between them (at least there's not in my working board). Can anybody please suggest what I should look at next?

[MikeB]

The other side of the switch connects to ground (0V).
You need to follow the track from the switch to the resistor on pin 11 and look for any solder splashes causing a short.

Mike.

[mpjf01]

I carefully inspected the track back to the resistor, no evidence of any shorts. So I cut the track between the SCK pad and the chip leg. It seems that the short is either in the chip itself or where the chip leg is soldered to the board. Does this mean that I have to try to find someone to replace the chip?

[ReSt]

Not immediately.
Find sombody who can CAREFULLY unsolder the processor pin in question and bend it up a little bit to get it free of board contact. Only if the pin then still has the 0 resistance to ground, he should change the processor. (Think of changing it to a more powerful one ?).

Reinhard

[jhsa]

Try using a magnifier and have a good look between the legs.. The chip's legs of course you dirty minds

If you can't see any short maybe the best is to try to carefully lift the leg/pin with the soldering iron and a needle, and see where the short is.. board or chip..

João

[MikeB]

If you can read and write the flash and EEPROM, then the SCK pin is not shorted to ground.

There is a 200 ohm resistor between the MENU button and the chip pin. Measure the resistance between the MENU button and pin 11.
Follow the track from the SCK pad down to the resistor (7th from the left). Below that is a via hole and then a small capacitor. That cpacitor connects to ground. Check round the via and capacitor for any shorts.

Mike.