QX7 will not turn on.

General Help and support for the Taranis Radio.
Post Reply
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

QX7 will not turn on.

Post by Marthr »

OK, I have an odd problem with a new QX7 and I hope someone can help. I flashed the XJT internal module to make it compatible with my existing receivers. It completed. I turned off and back on again and soon after it came on it went dead and would not turn on again. It wont even come to life if I hold the trims and press the on button, for USB mode. completely dead. Tried with different power sources (all checked around 8.4v) This morning I changed the main board with a brand new one - no change still dead. Also worth noting that with the TX off, it is possible to flash opentx-x7-en from the 2.2.0 companion, to either main board. However, still neither powers up.

Does anyone have any ideas ?

User avatar
MikeB
9x Developer
Posts: 17990
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: QX7 will not turn on.

Post by MikeB »

On the main board there is a fuse F1 and a diode D500. Check these are OK as the power goes through both.
Check also that the power button is still working. It connects to pin 11 of CON404, and should switch to ground when you press it.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Mike, many thanks for replying.

Any chance you could give me a way of locating the fuse. Which area of the board is it on. I will have another look and the print screen labelling too.

I had kind of ruled out it being a fuse on the board, as I have (as mentioned) tried a brand new main board, and the symptoms were identical. Which may suggest the problem lies on one of the other two boards.

Another factor is that I have successfully uploaded the opentx firmware to both of the main boards via the USB with the device off. It doesn't help, but it does suggest that the microcontroller is alive and kicking providing it gets power from somewhere. Obviously flashing the board made no difference to the symptoms.

Is there any way that the RF board could be involved in preventing power turning the system on. Is it used to interlock the supply to the main board in any way. Or can I rule out the RF board.

I may be left with the power button/board. But this looks like a PCB mounting some switches on it, and no electronics. What are the chances that a switch could just go faulty.

Any suggestions gratefully received.
Thanks
User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: QX7 will not turn on.

Post by jhsa »

MikeB wrote: Mon Sep 18, 2017 2:57 pm
Check also that the power button is still working. It connects to pin 11 of CON404, and should switch to ground when you press it.

Mike.
Mike just told you how to check the switch :) You can measure it.

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Thanks. Will do.

Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Assuming that :

- CON404 is the connector to the RHS of the LCD ribbon (and the one which goes to the power switch PCB), and that
- pin 1 is the Left most pin when viewed with the back off

Pin 11 (of 15) does NOT have continuity to 0v when the main power button is pressed.

What would cause a switch to fail ?
User avatar
MikeB
9x Developer
Posts: 17990
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: QX7 will not turn on.

Post by MikeB »

The USB cable supplies power when flashing with the power off. This confirms the 3.3V regulator is working OK, so it is just the battery connection and (soft) switch to investigate.
I'm just looking at the circuit diagram. If pin 1 is at the opposite end to that you assumed, then the pin you are checking will connect to the bottom pin of the external module connector.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Wow. That looks like the problem.

The question is whether there is a primary fault which caused this.
Attachments
20170918_182424.jpg
User avatar
Kilrah
Posts: 11108
Joined: Sat Feb 18, 2012 6:56 pm
Country: Switzerland

Re: QX7 will not turn on.

Post by Kilrah »

How did you flash the module?
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

I copied the frk file to the ad card, and used bootloader mode to flash it to the internal module.
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Thanks Mike for the info on the pinout for testing the switch. Is this circuit diagram in the public domain ?
Marthr
Posts: 14
Joined: Sat Sep 16, 2017 1:03 pm
Country: -

Re: QX7 will not turn on.

Post by Marthr »

Have now repaired circuit board and unit powers up and all seems fine.

However - the reason I was originally flashing the XJT module (with LBT/EU that I use in my Taranis Plus) is that it would not bind to any of my receivers. My Taranis Plus (on the same firmware) does bind fine.

I will raise a separate thread for this, but thanks to Mike and everyone else who has posted on this one.
User avatar
MikeB
9x Developer
Posts: 17990
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: QX7 will not turn on.

Post by MikeB »

Marthr wrote: Mon Sep 18, 2017 9:11 pmIs this circuit diagram in the public domain ?
No, it is released by FrSky under a NDA.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!
acidjunkie1980
Posts: 3
Joined: Fri Aug 09, 2019 10:11 am
Country: -

Re: QX7 will not turn on.

Post by acidjunkie1980 »

mine have the same problem now for 5th time ..the other times powered on but tapping fast the power button and plugging in and out the usb cable but now its not...did you figure any fix for this man?

Post Reply

Return to “General help (FrSky Taranis radio)”