openrcforums

I've tried forum search as well as some google searching with various keywords and site filters with no luck.

How should I go about finding the schematic for a Q X7 on openrcforums?

You'll have to reverse-engineer it yourself
There are no published schematics for FrSky equipment, like most other commercial devices.

Ah...I thought I had read over on.....Ersky9x Coding ???? thread talking about different revs as *if they had been looking at the schema.

Q X7 and X9D/+ have same processor?
How could mike port ERSky9x without knowing the pinouts were the same? Or did he just reverse engineer it, himself/someone else?

Mike, and a few others might have the schematic, but they cannot give it to others.. Do you really think Frsky would like them to reveal their secrets to the public??

João

A few developers have a NDA with FrSky, so we get technical documentation, but it does mean we can't release it.

We can, however, make use of the information to assist with solving problems.

Mike.

Ahhh...I didn't realize Mike and others were in good like that with FrSky (access to sensative info with NDA).

It all makes total sense though!

Thanks,ya'll!

MikeB wrote: ↑Thu Aug 10, 2017 1:56 pm A few developers have a NDA with FrSky, so we get technical documentation, but it does mean we can't release it.

We can, however, make use of the information to assist with solving problems.

Mike.

Hey Mike, i saw this old post from you and was like "Oh my god, maybe he could help me" so i registered here
I have the Problem with my QX7 that a friend of mine broke off the USB port and it looks like he damaged a few SMDs there... I'm not a specialist about measureing SMD parts -.- So i wanted to ask you, if you could tell me what SMDs are used there at the USB port including the capacitors, if you have the schematic from the QX7? I don't need the shematic itself i am only interestes in these few SMDs there :/
Would be rly nice if you could help me out

Kindest regards
Medin

R503 and R504 are both 22 ohms.
C501, C502 and C503 are 100pF.
C504 is 4.7uF.
Devices beginning with DT are ESD protection devices, I don't know their part number.
FB500 is in the USB, 5V power connection, so I would guess it is a fuse of some sort, possibly a thermal, self resetting fuse, again I don't know the part number.

Mike

Thank you soo much Mike, you helped me a lot.
The SMD code is written on DT so i have it already(it is ZV831BV2TA if someone need it).
Again thank you a lot.
Best Regards
Medin

MikeB wrote: ↑Fri Feb 22, 2019 4:57 pm R503 and R504 are both 22 ohms.
C501, C502 and C503 are 100pF.
C504 is 4.7uF.
Devices beginning with DT are ESD protection devices, I don't know their part number.
FB500 is in the USB, 5V power connection, so I would guess it is a fuse of some sort, possibly a thermal, self resetting fuse, again I don't know the part number.

Mike

(forgive my bad english)
hey Mike, I recently tried to do the tbs crossfire mod on my qx7 when I accidentaly desoldered some resistors and lost them (the circled ones in the picture). I was wondering if you could please help me because I don‘t know the name of those resistors and would like to order them.


kindest regards
Mr.Despar

R104 and R106 are both 1M. They are both on JTAG signals and are used to tell the processor what hardware revision the PCB is.
Both are fitted on the rev 0.4 board.

Mike

thank u so much mike!

hey mike sorry to bother you again, but would you link me those pieces because I cant find them anywhere.

Mr.Despar

Do a search for "0402 1Mohm smd resistor".

Mike

MikeB wrote: ↑Wed Jan 29, 2020 3:35 pm Do a search for "0402 1Mohm smd resistor".

Mike

hey mike, I spent a couple of days searching for this 0402 1Mohm smd resistor (and asked some friends) but there are hundreds of similar resistors with different voltages. How do I select the right one (which voltage and stuff like that). Could you also help me find the C109, C115, C125 please, that would help me so much because I just got into this hobby.Thanks again!

kindest regards Mr.Despar

MrDespar wrote: ↑Tue Feb 04, 2020 7:40 pm I spent a couple of days searching for this 0402 1Mohm smd resistor (and asked some friends) but there are hundreds of similar resistors with different voltages. How do I select the right one (which voltage and stuff like that). Could you also help me find the C109, C115, C125 please, that would help me so much because I just got into this hobby.

Maybe you should select another hobby

cu KH

kalle123 wrote: ↑Tue Feb 04, 2020 8:28 pm

MrDespar wrote: ↑Tue Feb 04, 2020 7:40 pm I spent a couple of days searching for this 0402 1Mohm smd resistor (and asked some friends) but there are hundreds of similar resistors with different voltages. How do I select the right one (which voltage and stuff like that). Could you also help me find the C109, C115, C125 please, that would help me so much because I just got into this hobby.

Maybe you should select another hobby

cu KH

well I fly Fpv drones but I‘m just awfull at this stuff...

Hi MrDespar.

I did not want to affront you, but writing 'searching for this 0402 1Mohm smd resistor (and asked some friends) but there are hundreds of similar resistors with different voltages.' makes me think, you and 'your friends' have to really learn a lot, before putting hands on a PCB board, trying to repair.

br KH

For resistance as far as I know there is no voltage limit. There is power limit. And normally on SMD the size dictates the power.
I also agree that if you never had contact with electronics and specially fine soldering, that might not be a job for you..

João

jhsa wrote: ↑Wed Feb 05, 2020 11:45 am For resistance as far as I know there is no voltage limit. There is power limit. And normally on SMD the size dictates the power.
I also agree that if you never had contact with electronics and specially fine soldering, that might not be a job for you..

João

thought I could get away with just buying those missing pieces and solder them on instead of buying a new motherboard for my radio. I didn‘t know that this would be such a complex problem. I was just trying to do the best I could because a new mainboard would be like 60 -70 bucks

You can try. But you be aware that things can go wrong very quickly, even if we are experienced.

João

The voltage applied to these components is only 3.3V, so you should find suitable components quite easily.
It would be easier if you could post a couple of links to components you are able to get then we can confirm they are suitable.

Mike

Soldering those 0402 requires the necessary equipment (soldering station with fine tips, tweezers, fine soldering wire - preferable lead wire, flux ...) and at lot of ROUTINE!! Before starting on the PCB, you should question yourself.

If you have the slightest doubt, leave it and 'a new main board would be like 60 -70 bucks' is certainly cheaper.

I personally have a very long experience with soldering. 1206 or 0805 is still OK for me, but I have to admit, with 0402, this is a no go for me.

br KH

I do 0603 fine, and even find it easier than 0805, go figure
Never tried 0402 as I don't own any yet.. I will practice with a grain of sand though

João

EDIT: I don't use a fine tip for the resistors either. I use a small flat tip. That helps to spread the heat more evenly across the component and the pad.

Thank you guys so much for the advice
Just one more question. If I buy a replacement qx7 mainboard rev. 04 even though my current one is a rev. 06, will the radio still work?
From the minor version jump I would assume it should work, but I'm not sure about the compatibility.

kindest regards Mr.Despar

I think that should be OK. Mine is before rev. 0.4 and works fine except for the SPort in the base. That issue was fixed on the 0.4 board.

Mike

Hey Mike,

dont know where or whom I should ask but could you tell me which pin of the STM32 is used for S.port/CRSF (etc.) output? And if we could directly solder to the pin to get the signal (maybe use the crossfire inverter board?).

I ask because I want to try to get an external module running on the BetaFPV Lite Radio 2 which supposely uses the QX7 target (with minor modifications)

I'm hoping that one of you people with access to the schematics can answer a question about the Q X7 radio board...

I was replacing the antenna, and I may have knocked L5 loose. It's a tiny SMD right next to the antenna connection. I tried to put it back in place and the transmitter seems to work, but I'm wondering what the impact would be if it were actually disconnected. Would the effects be negligible? Or would it effectively disconnect the antenna?

digaus wrote: ↑Thu Jun 11, 2020 8:37 pm Hey Mike,

dont know where or whom I should ask but could you tell me which pin of the STM32 is used for S.port/CRSF (etc.) output? And if we could directly solder to the pin to get the signal (maybe use the crossfire inverter board?).

I ask because I want to try to get an external module running on the BetaFPV Lite Radio 2 which supposely uses the QX7 target (with minor modifications)

This may be of help. On Philipp Seidels site there is a photo of a naked pcb. He has marked the trace of the SPort.

MikeB wrote: ↑Fri Feb 07, 2020 11:21 am I think that should be OK. Mine is before rev. 0.4 and works fine except for the SPort in the base. That issue was fixed on the 0.4 board.

Mike

Could you help me find the R419, R418, R101, R102, C123 please