Strange behaviour after range mod

So i got around to doing the range mod. I used solder 'glue' to short the diode without removing it. I am confident that that all went fine however im now getting strange behaviour from the tx.

I get a high pitch whine when i turn on the tx.

Next the main screen only shows the model number, voltage and output. The menus work fine and every setting can be changed no problem.

What should i be looking at or have i toasted the module and need to add a 8S module?

Thanks
Alex

The sound is from the speaker picking up the amp RF. You have the shield reinstalled?

The strange looking main screen is because you likely installed one of the later nightly firmware.

The main screen GUI got some added feature. So if you're using an older model created before the main screen GUI change, then you'll have to enable the features you're used to seeing. i.e. timer, graphics, trims, stick outputs, etc.

So it sounds like everything is working right so don't be alarmed.

Yeah im pretty sure that i got the shield down properly. I'll try and redo it all.

I did have an issue of it not turning off when i flicked the switch, and had to pull the battery, but that seems to have stopped since i updated to the nightly and replaced the batteries.

I also cant seem to get it to recognise the usb driver now. Doh.

I wouldn't worry too much about the noise. If you output at the 10mw. It should be just like before.

I've only has the not turn off issue if I let the battery run too low. Then the Devo7e start to act funny. Like not turning off immediately.

Okay so i resoldered the rf shield and made sure its perfectly flat. I now have a tx that only turns on for a second or so then truns off, and wont turn on again unless i unplug the internal connector (on pcb board) for the battery. Whine is still there but that may be due to the placement of the antenna cable.

What is the small black thing screwed to the pcb on the right hand side? It seems to have a small shaft that comes out the side. Ive managed to melt the edge of that with the soldering iron and am wondering if thats whats causing my issue?

So ive traced the power issue to a slightly dodgy power switch/connector. I reseated it and seems to stay on now.

My main issue now is the buzzing when the tx is on. I have tried moving the antenna and the speaker around to stop it but it stays on no matter where they are placed. It also doesnt get quieter if i change the output either, just stays the same volume all the time. Its quite loud and quite annoying if i was to use the tx to fly.

Apart from disconnecting the speaker is there anything i can do?

Thanks

It sounds like something's wrong then. Not the normal sound we're used to hearing if it's that loud and annoying.

Hope something can chime in to help. I am out of ideas.

Yep something is definitely wrong as the turn on/off issue came back and then a couple of little puffs of smoke came up from the largish silver component (rectangular with round ends) to the left of the module. It still turns on but will turn off within a few seconds. After repeating this a couple of times it wont turn on at all and I have to wait a few minutes to be able to turn it on again.

Video

I dont really have any electronics knowledge so fixing this may be out of my relm unless its just replacing one if the larger components.

Well now she is truly dead. Wont turn on at all. Now i may have dropped her but it was only from a couple of feet. Still no response at all.

What compnents should i be testing to see if the power circuit is fried?

Anything else i can test to find a culprit?

Dont think i shorted anything, i had a good look and made sure it was all clean.

Desoldered the module and still nothing. What is the large silver component left of the module with TKD8.000 written on it?? Im pretty sure that sent up a little puff of smoke shortly before she died for good.

It now seems to flash the screen for a second when i turn it on but only for a plit second. Seems like the power circuit is damaged. Is the quartz part of the power circuit?

Im pretty sure it was this that gave out a tiniest puff of smoke at one point. I cant work out if the cap circled is burnt from the solding iron or it burnt out. Would it be a potential culprit of no power?




Id love to try and fix this before shelling out for a devo 10.

Thanks for the help.

I think its maybe just down to a short that has occurred during the two or three times ive taken off the shield and/or when i shorted the diode for the range mod. I dont know enough about electronics to be able to truly troubleshoot it hence all my questions. Ive looked over the board many times and cant see any obvious damage. I do remember one of the last times the lcd came on and showed the voltage it went from around 4.90v up to 6.90ish and back down quickly. Does that shed any light on a problem?

I think this may be a throw away. I know its only a $60 radio but im still annoyed with myself. Doh. Its probably not even worth taking to my local repair place as it would probably be more than $60 just to look at it.

Now maybe i should be asking Devo 10 or 9XR with Orange module? Both will cost me about the same money to get to my door.

Alex

So reading one of the other threads about someone's Devi 10 blowing the npn and pnp trasistors, I'm wondering if it worth a shot to try and replace them. Are the transistors I've circled the transistors from the power circuit?



Ive resoldered fets ontoo a micro heli board before successfully so im not completely afraid of trying but as it stands the 7e is a paper weight as it is.

I've put arrows on your picture. You need to short them together and switch on which will buy pass npn/pnp. If it works DON'T!!! use as it is. All it will tell us is PNP/NPN are one of them is duff and there are other things that stop working once you bypass that.
Apologize I haven't don't circuit as yet of Devo7e but if you look for Devo10 circuit its pretty much the same thing, PB did the drawing I don't have link link handy, sorry.

Ps If it all goes horrible wrong blows up and burns down your home...town
Sorry you do this at your own risk

Shorted the two points at it still won't turn on. I still just get a flicker of light from the LCD but that's it. Does this lead you to any other ideas?

After a really close inspection of the board, i can see a small burn/melt mark on the bottom black part of the crystal. Sorry for the poor photo, cant seem to find my normal camera.




I can get it to go to the firmware update screen by holding down EXT, but i have to let it sit for a while and then plug the battery back in and switch on. If i swtich it on normally a couple of times in a row it wont flash the lcd after about 3 or 4 flicks of the switch. When i plug it into the computer when i have the firmware update screen on, my computer wont recognise the usb device eg it gets a code 10 cannot start error so i cant use the updater.

Okay so a little bit of progress on this situation. Even though the tx has routinely not been recognised by my computer as in DFU i decided to plug it on today and try it one more time, and wahey! Recgonised. So i reflashed it with 3.0 and all went well. Now i have a tx that turns on and seems to function as per normal BUT now when i turn her off, i cant turn her on again without waiting for a minute or so.

Any thoughts?

Alex