[heebyjeeby]

Hi,

My RX unit has fallen from a window sill on to a stone tiled floor, largely thanks to an overexcited puppy.

It must have landed on the RX aerial, as it bent a bit and cracked the pcb. It stopped receiving from the tx   . I tested and found continuity between the central pole of the SMA connector and the exterior ground, which I think indicates a short somewhere.

I attempted to desolder the SMA connector, it hasn't gone well     . I was trying to prise the connector off while heating the legs, and it just snapped as shown. 

   


Is there anything I can do here or is it a case of getting a new RX board? I have a spare SMA connector, aerial and RX 433mHz  receiver module.

Thanks.
Heeby.

[werk_ag]

Hi Heeby,

I'm sad about what happened to your board. Let's be positive... I may not be so bad as it seems.
With some care and effort I think it can be repaired, at least it deserves trying.

Things to check:
* Is there any short between the 5V and ground?
* Check the underside of the board, near the place of the SMA connector there is a 5V trace that goes from the Meduino 5V pin to one of the RF receiver pins. Check if the trace isn't damaged! If it is damaged, check if it is not causing any short to GND, and do bridge using a small wire.

Again, with a small wire, do a bridge between a GND point and pin 1 of IC4. Don't worry if during welding you do a short with pin 2, because pin 1, 2, 3 and 4 are all connected to GND.

Carefully, try to remove anything that still remains connected to the ANT output on the RF module. Get an piece of isolated wire of around 17.5cm (preferably a non flexible wire) and weld it directly on the ANT pin of the RF module.

This should be enough to bring your receiver back to life.

I'm attaching a picture which may help you with the repair

   

[heebyjeeby]

Thanks Werk.

I have bridged the 5v and ground tracks, it looks and tests like it should work..

I have tried soldering 17.5 cm wire to ANT, but this is testing as shorted..
You probably couldn't see from the picture that the ANT peg has snapped from the module and there is not much to solder to. 
Here is a better picture.

   

Soldering just to the ANT connection is very difficult (impossible?)
My guess is that if I replace the RX module,and solder wire to ANT, the whole board will work properly again.


I thought I had another RX module, but I don't, so  have ordered some of these from China but they will probably take a couple of months to arrive. They are what I originally bought.

Would one of these work ok - it's a little bit more expensive, and different to the ones I originally got, but from the UK so I could get it in a couple of days. Not sure I have the patience to wait for the China delivery!

Sorry for all the questions,

Thanks,
Heeby

[werk_ag]

I have bridged the 5v and ground tracks, it looks and tests like it should work..

Soldering just to the ANT connection is very difficult (impossible?)
My guess is that if I replace the RX module,and solder wire to ANT, the whole board will work properly again.

Yes, it should work. Using a simple wire antenna can work as well as an antenna connected to the SMA connector.

[heebyjeeby]

Just got around to soldering in the new RX module and ...it all works! I have simply soldered some wire to the ANT pin for an antenna.

Actually, the range is even better than before - signal is going through 3 stone walls of about 50 cm thickness, and about 80 metres to get to my shed. Efficiency is only about 50%, but couldn't get a signal at all in my shed before  - the RX had to be in my kitchen, about 50M and one wall from TX. I will play around with the system tomorrow to get efficiency a bit better.

Pleased to have weatherduino working again.

Heeby

[hornychz]

Congratulations, Heeby! 

[werk_ag]

Just got around to soldering in the new RX module and ...it all works! I have simply soldered some wire to the ANT pin for an antenna.

Actually, the range is even better than before - signal is going through 3 stone walls of about 50 cm thickness, and about 80 metres to get to my shed. Efficiency is only about 50%, but couldn't get a signal at all in my shed before  - the RX had to be in my kitchen, about 50M and one wall from TX. I will play around with the system tomorrow to get efficiency a bit better.

Pleased to have weatherduino working again.

Heeby

You should thank to your "over excited puppy".
I'm glad to know that your system is working again even better than before. Some times a single wire works better than some types of antennas.
Thanks for the update.