Sonoff Dual R3 Esp32 damaged trace

[digitally-dad]

Hi,

I've managed to damage the 3v and rx trace on this board, I've cleaned up the areas and ordered some conductive foil to repair, I have a couple of questions hopefully someone can help me with.

Is the foil suitable for this repair?
I have circled in red the 2 points I believe need to be joined, does that look correct? I couldn't find any schematic for this board, I'm not entirely sure it would have helped me with this repair if I had..

I've also pulled the trace on the RX(blue circle), I've already successfully flashed the device with Esphome, so I don't care if I can't connect to the Rx point in the future, but is there any repir needed at that point, currently the board is dead when connected to AC, I'm hoping that fixing the 3.3v trace will fix that.

Any support appreciated

[TD-er]

First question is how the trace got damaged like this.

Is it due to prolonged soldering and thus delaminating the traces from the PCB?

Before attempting to fix it, maybe you can see if other parts of the board may have been damaged?

I don't know how the PCB of this board looks like, but if I'm not mistaken these are quite small modules to fit in a wall behind a switch or power outlet.

So if your repairs are close to solder pads which may carry mains voltages then I would advice against it.
Your fixes may add some extra 'height' from the PCB which may then give room for sparks to occur.
Traces and pads connected to 230V AC should at least have a distance of 3 mm from each other, preferably more.
If your traces are covered with solder mask (the green paint on the board), they can be closer together, but since you need to replace those traces with something I doubt you will meet these requirements.

[digitally-dad]

They weren't damaged by current, I had solderd wires for flashing Esphome, they got yanked during testing, 1 of the joints broke(tx) but the other 2 pulled the trace off on me so no other damage will be present.

Yeah they are relatively small modules, and can go behind a switch, this one won't be though, it was going to be used to fire a boiler, with integration into home assistant.

I have a replacement board ordered, but wanted to try repair this in the meantime, I don't want to use anything that is a risk though, I was planning to cover the repair also.

Thanks for the information TD-er

[Ath]

I made a photo of my Sonoff dual R3 board of ca. the same area, maybe you can use that in the reconstruction/renovation

PXL_20240902_192526887_reg001.jpg (865.58 KiB) Viewed 4363 times

[chromo23]

Any support appreciated

Hey,

the repair is actually quite simple but i strongly recommend to use wires to brige instead of foil.
Bridge the red circled areas.
The blue circled area doesn´t need repair since you can solder a wire directly to the solder joint of the board

[TD-er]

The GND is also exposed there, so make sure you do not create a short.