Hello,

I have a Happymodel ELRS EP2 RX connected to a Moblite7, but since my last crash it has stopped working. It was not a hard crash, but still...

I have a canopy on the Moblite7, so the RX has not taken a direct hit, because it was covered by the canopy, but it is obvious that the crash has done something to it.

When I plug a battery on the quad, the green led on the RX stays solid, but with a very dim bright and it is not binding to the TX.

I have checked the cables, i have tried to resolder it but the problem persists.

The TX is not the problem, as i have another quad with a EP1 RX and it works with no issues.



Any idea what can be damaged? Anything i can check or do to fix it?

Thanks in advance for your help

You will need to inspect the RX under some magnification to see if any components are knocked off or damaged.

The dim light seems to indicate a power issue but you claim the wiring is ok. Did you check with a multimeter if the FC is providing the correct voltage to the 5v pad of the RX?

(20-Jan-2022, 05:49 PM)kafie1980 Wrote: You will need to inspect the RX under some magnification to see if any components are knocked off or damaged.

The dim light seems to indicate a power issue but you claim the wiring is ok. Did you check with a multimeter if the FC is providing the correct voltage to the 5v pad of the RX?

Thanks for your answer!

I haven't tested the voltage delivered to the RX, that's true and one of the first things i should've done.

I do have inspected it under a magnifying glass and i see no componets ripped of, but i have seen that a plastic cover of one of its chips seems to be scratched or even a little bit burned, hard to tell... this thing is so small!
I will give it another try and also i'll try to get some pictures, but the first thing will be to test the voltage delivered.

This quad had its internal RX damaged out of another crash, or at least it stopped working, the ufl antenna that it came with fell of and since then i was unable to make it working again, even with brand new antennas. That's why i jumped to ELRS with it.
Maybe the whole board is on his final breath.

Again, thanks for your answer.

I've just tested the voltage as suggested and it seems to be fine. I've done it at the Moblite7 board pads and also at the RX pads and the readings are about 4.92~4.94v, so this doesn't seem to be the issue.

I'm attaching here two pictures, hoping to get some clues.

PS: Attaching doesn't seem to work, so uploading them somewhere else

Remember the Happymodel hardware defect ?
https://intofpv.com/t-happymodel-epx-exp...are-defect

It may be worth getting the glue smudge off that chip and checking if it is the same one as in the other post.

A thought 

Scott

(20-Jan-2022, 08:32 PM)Scott_M Wrote: Remember the Happymodel hardware defect ?
https://intofpv.com/t-happymodel-epx-exp...are-defect

It may be worth getting the glue smudge off that chip and checking if it is the same one as in the other post.

A thought 

Scott

Thanks for linking that thread.

I've read about this issue somewhere else, can't remember where but I think it was on Github.
I've tried to clean that chip, but it doesn't seem to be glue, but burned plastic or scratched.
I've sent an email to the vendor, hoping they accept to replace it.
Anyway, thanks to all for your help