9xr pro freezing up help please

[jonrev]

Wonder if anyone can help with 9XR pro problem. Bought as faulty and when first tried all seemed ok for a few minutes at a time then a line of corrupted screen display and the Tx froze up. On/Off switch still worked and would start again ok. This problem repeated each time I tried setting up the unit. No obvious operation caused it to freeze just at random times. Nothing seemed to be getting warm and no obvious signs of problems. Only visible damage is that the trainer momentary switch wires had been removed and taped up. The switch looks to be bent and I suspect it was from being dropped at some time. I taped the wires together and the TRN switch went from on to off on the diag screen.

Tried reflashing the firmware several times using both ersky9x and opentx and reformatted and reloaded the SD card several times. Even reflashed the bootloader just in case. All these operations went fine but made no difference to the freezing problem.

Over the course of a few hours of fiddling things became worse and on switching on a brief screen of corrupted lines then the startup screen only got to splash screen stage before freezing. After leaving the Tx overnight I tried again this morning and all was well for about 10mins before it froze again and now will only show the corrupted screen then splash screen picture and freeze. Again nothing seems to be heating up at all that I can feel. I did notice as I was going through the setup pages that the display was fading then sharpening again from page to page.

Does all this suggest anything as the likely fault to anyone? I wondered if the processor was the problem and don't mind trying to swap out but I suspect my chance of doing so successfully is slim with my aged eyesight and shaky hands? Did wonder if there was a faulty ceramic oscillator thingy (I've read on here about faulty ones) but the pro doesn't seem to have one? You might be able to tell that my digital electronics knowledge is minimal but I know the knowledge base on here is impressive enough to possibly point me in the right direction.

Thanks for any suggestions

John

[MikeB]

Is the "freeze" just the display? If you bind to a receiver, do servos still work when the display is frozen?

Mike

[jhsa]

If the LCD was fading, you could probably take some voltage measurements to see if the radio voltage regulators are providing the right voltages. Are you able to do this?
At the moment, I have no idea of what the problem is..

Joao

EDIT, I can see Mike also responded, please follow his advice..

[jonrev]

Hi Mike and Joao. Hoped you might be about.

When the freeze happens then nothing responds at all- no sounds or voices but till then everything works as it should. The display only started to 'flicker' the last time I was messing with OTX settings and hadn't happened before so I suspect it was just a one off. I'm now back with er9x and screen seems stable.

Now it starts ok with voice and usual throttle warning etc for a new firmware install. I can cancel as usual and maybe get past the splash to a settings screen but freezes up pretty quickly so don't get a chance to do much.

While I am flashing backwards and forwards with firmware via eepskye or companion there is no problems at all and flashing works fine but the same problem is there with all firmware once it's flashed. I can't flash from the SD card. Tx will start ok with trims inwards and show bootloader v1.1 ready and a list of the firmware files but no response from buttons at all so can't select or activate.

This is only a 'project' Tx so am not desperate but it would be nice to sort it. If not it can live in the spares drawer till needed.

Thanks guys

John

[jhsa]

try without SD Card please..

João

[jonrev]

Hi Joao. Just tried without the card and seems much the same. About 1 minute till freeze up. Screen fine and calibrated sticks fine but after checking version I went to general radio settings and it froze again before I could do anything else.

John

[jhsa]

Is the battery fully charged? You might have to open it and start measuring voltages.. But wait to read Mike's opinion please..

João

EDIT: By the way you still didn't answer Mike's question? Does it work with a receiver connected and does it move some servos??

[jonrev]

Yes battery is fully charged. Can't try it as it won't stay on long enough for me to set up and bind to a receiver at the moment.

I'll try it with a multimodule set up for a BNF quad as soon as I can get as far as a model protocol setup screen.

Thanks Joao

John

[jonrev]

Hey guys I just managed to get the Tx set for PPM, 12 channels with AETR order and put one of my little NRF multi's in it where you set model by holding a stick position when switching on the Tx.

Bound fine and let it sit a while. Sure enough the display soon froze and no sign of stick or switch operation BUT... The little quad was under control with no problems?

So does this mean that the major bits of the Tx are working ok and just the display is the problem?

[jhsa]

So, even with the display frozen you still had control of the model?

João

[jonrev]

Yes I bound it while the display was working then just put it to one side and fiddled with the Tx till the display froze again and no signs of life but the quad was still bound and flying fine.

[jonrev]

Just to appologise to Mike and you for doing what I see so many people do when asking for help on these forums. So often I read these threads and you and Mike say 'try .... and let us know what happens and the poster merrily does something completely different without answering the question. Frustrating for you both.
The only thing that's even more annoying is the poster who just disappears after you spend time trying to help and never even lets you know the outcome. 'No good deed goes unpunished' as Judge Judy so often says

[jhsa]

No problem
I don't know what to think.. do switches and pots work? Do the navigation keys plus menu and exit keys work?
Just trying to find out if it is really just the LCD.
You could open the radio and check the LCD ribbon is well connected.. HHmmmm, but this doesn't explain that the radio works again if you reboot it

João

[jonrev]

Yes a puzzle. I think the buttons are probably working after a freeze up as I still get the little beep if I push them but obviously I can't see anything happening on the frozen screen.
Difficult to even guess what might be happening without a circuit diagram showing where the screen data is coming from. Presumably it's from the CPU originally but via what other components. I wonder if there's some kind of chip taking signals from the CPU and turning them into a screen driver format which might be faulty or losing it's power supply somehow? I'm probably spouting nonsense.

Maybe Mike will be along some time and have more info and suggestions. I'll keep monitoring this and see. Meanwhile thanks for the pointers so far and I'll have a probe around inside again tomorrow and check the ribbon cable.

John

[jhsa]

Yes, but please be gentle with it

João

[jonrev]

Just been looking round for anyone else with similar problem and found an old post from Xibel who had exactly the same problem with a couple of 9x's and put a vid of the behaviour on youtube. Both of you (Joao and Mike) replied with help but, like so many on here, the poster disappeared without letting you know the outcome. I have messaged him to ask if he had any joy with his units but he doesn't seem to have been around for a long time.

Mike seemed to think a bad solder joint was most likely so I had a good look with a magnifier but can't see anything. Half the lines from the screen ribbon seem to go to 16 pads marked 'expansion bus' and the others seem to mostly go to through board points. Unless any further suggestions today I guess I'll remove the board and look at the back side and start resoldering everything.

John

[jhsa]

Please check that the LCD ribbon is straight and well inserted in the connector..
also, with the plastic handle of a small screwdriver, make some gentle pressure on the processor to see if the problem goes away. Be careful not to short anything.
Measure the voltages on the 3.3V regulator. again, be careful not to short anything while doing it..


João

[MikeB]

Definitely check the ribbon is connecting OK.
Also, with power off, use a needle or pin and gently push on the pins from the LCD connector where they a soldered to the board. If one is not soldered it will move with slight sideways pressure. I often use a slight "flick" resulting in a small noise. You will soon recognise a different sound if a pin is not soldered.

Mike

[jonrev]

Hi Mike and Joao. Thanks for coming back.
Well I removed and reconnected the ribbon cable and it's seated nicely. I went over all the pins of the ribbon connector and the CPU with pin and magnifier but no sign or sound of a non-soldered joint. Also checked visually the caps etc round and near the area but nothing seen.
The VRegs give 5.1 and 3.29 volts both while all is working ok and when the screen freezes which it is still doing as before.
Would it be worth removing the mainboard and looking at the back side or is there nothing there likely to be problematic? Can't remember if the LCD screen is fixed to the board or not on this Tx but can't see any fixings. Didn't think there was anything electronic at the screen end of the ribbon anyway apart from the display element.

[jonrev]

PS- I had a look round the other day for a spares supplier for the 9xr pro but found absolutely nothing. Seems like they are a completely dead radio now. Guess that's the way of things as tech moves on. Had thought I might be able to get a mainboard and/or screen to salvage this one but seems not.
I could always buy a new one on Amazon for a very reasonable £350 plus shipping?????????????????? Yes that's right. Couldn't believe it but Amazon UK have it on sale now and that's without a module too.

[jhsa]

350?? : o Isn't that a bit too expensive?

João

[jonrev]

Well HK have it for about £85 if I remember correctly and I thought that was too expensive. For £350 you could get two Taranis's and I know which I'd sooner have.

Just took mainboard out for a closer look and will redo some solder joints on top side. Surprise was when I looked at the bottom. Should be a pic of what I found.

Now I don't suppose this is my problem but the socket pin soldering looks really corroded. Almost looks like it's been very damp for a while. I'll clean all these up and resolder tomorrow and try again. If still no joy I may just give it up and move on to something else.

I'll post here how I get on.

John

[jhsa]

It doesn't look very good

João

[jonrev]

Well I've cleaned up and resoldered all poor looking joints on the bottom of board and also most of the caps etc near the ribbon connector on the top. No luck I'm afraid. Exactly as it was before.
I've taken a pic of the line of corrupted display that happens most times as it freezes.

Since all ribbons and connectors have been removed and replaced at least once now I doubt it's a bad contact on one of these. No sign of any other bad soldering and no components look suspect. Nothing gets warm before it happens that I can feel and nothing I do by way of putting pressure on CPU or board in general seems to have any effect. I think it's time to admit defeat.

I don't think I have the equipment (soldering iron) or ability (steady hands and eyesight) to think about replacing the CPU even though I'd quite like to. My first thought was to just get another mainboard but after looking for one it seems that's not an option now. Maybe a 'Pro will come along with other faults at a sensible price but till then I'll just put this one away.

Thank you Joao and Mike for your help and I'm pretty sure it won't be the last time.

John

[jhsa]

I wonder if it is the display itself..

João

[MikeB]

On the test versions thread I've just posted a special test version for the 'PRO.
This does 2 things:
1. Slows the clock to the display down.
2. Resets the display if you pull the THR switch is towards the front.
So, please flash this, then power up with the THR switch away from the front. See if the display freezes. If it does, switch the THR switch towards you then back away and see if the display starts working again.

Mike

[jonrev]

Ok thanks Mike I'll do that and get back to you.

John

[jonrev]

Mike- no that made no difference. All freezes as usual. Pulled throttle sw and display went blank and didn't return when switch was pushed back again. Tried twice with the same result.

[MikeB]

The display going blank indicates the processor was still running normally, and also that the display was responding to the reset signal.
It does seem it is only the display, or the connections to it, that are the problem.
Things you could check are:
1. R60 is connecting to pin 1 of the display connector, is of value 2K2, and the other side is connecting to ground. Check R62 is not fitted.
2. Check capacitors C9 through to C17 all look to be well soldered. These are all related to the LCD generating the voltages it needs to work.

Mike

[jonrev]

R60 is there and between display pin1 and ground shows 2k2. R62 isn't fitted. Will check caps you mention tomorrow in daylight and make double sure soldering is good. They all show OC with the meter. C7 and C8 must both have parallel circuitry as both show about 370R.

Catch you tomorrow.
Thanks
John