Seems to have received faulty unit. How to diagnose the problem?

[tarkani]

Hi,

I bought a couple of Faikout devices, but one of them doesn’t power on. I could return it to Amazon UK, but since I live in Turkey and already brought the devices here, customs costs would be high. It would be easier for me to fix it locally. Can you help me diagnose the issue?

I have 5 Faikin devices in total, all controlling the same model Daikin Siesta split AC unit via the CN_WIRED connection. Four devices work fine, but the LED on this one doesn’t light up. I also checked if it broadcasts Wi-Fi in case the LED is disabled, but it doesn’t.

To confirm the AC unit isn’t the problem, I tested another Faikin device on the same unit, and it worked.

I inspected the connector and traced connectivity to the pins on the back of the board. I didn't find any shorts and connectivity seems fine.

Thanks!

[revk]

If you are able to connect a USB-A to the 4 USB pads on the back, you may be able too use the ESP IDF (idf.py) code to access it and see if it is doing any serial logging, etc.

But it is also possible it is faulty. We test all before shipping, but if something is marginal then it is possible to be broken later.

But checking it even "appears" as USB device would be a good test. (not at same time as connected to a/c).

[tarkani]

Thanks for your quick reply. I will work on it later today. Cheers!

[tarkani]

Hi again, I finally got around to getting the faikout soldered (I don't trust my soldering skills). When I connect it to the computer, it keeps cycling connection/disconnection sound. Device manager refreshes so quickly that I cannot see how the computer detects the faikout.

Any suggestions?

[revk]

That sounds like it is crashing perhaps, though usually that stays connected at USB, so could be faulty hardware. Simplest may be return as faulty - do they really make it that hard? I understood amazon resold items like this locally, but perhaps not.

[tarkani]

Hi, I will buy a new one and not return the old one. Happy to support your project!

[revk]

Sorry about that, thank you.