Report - FTX24NMVJU not working

[turnrye]

Hiya,

I just received a few faikins from amazon uk, thanks for making them so easy to get. I have a FTX24NMVJU that has a KRP980B2E installed to get an S21 port. I connected S21 with jumpers, ensuring that it was a straight through cable, and the faikin turns on, however the debug feature via mqtt shows the following:

debug:

{"protocol":"S21¬Tx","cmd":"F1","noack":true}

dump:

{"protocol":"S21¬Tx¬Rx","dump":"0246317703","F1":""}

Faikin-S3-MINI-N4-R2: 4cc882f

I tried two different adaptor boards in the off chance that it was a bad board but got the same result.

[revk]

You can lock settings to S21 only and not inverting tx and rx which helps avoid it cycling through options.

But if, even then, it just comes up with noack, that suggests something not connected right.

I'm assuming the topic on that second MQTT end tx

[revk]

OK I wonder if anyone else has used this board and can advise.

What voltage is on pin 1? (using pin 5 as GND)?

[turnrye]

Just measured +4.98VDC across pin 1 and 5. This also is consistent with the +5V that's printed on the board nearby (that via feeds pin 1 through a trace on the bottom of the board).

[revk]

OK that is good, so I am at a loss as to why this is not working.

Do you have a second Faikin to try?

[turnrye]

I do! I will try that. I also have a few more of these units in this series (various BTUs), so I can try different Daikins too :).

I will report back in about 12 hours with results.

[turnrye]

Actually I had another minute and plugged in a different faikin. This one worked immediately 🎊 . So at this point, we can treat the original post as resolved.

I'm still curious to understand why this is happening. So later when I come back, I'll compare the configurations and settings side by side later to understand if this is a configuration issue or a hardware issue.

[turnrye]

Got a few more RX dumps since my original message:

{"protocol":"S21","dump":"024771313348516503","Gq":"13HQ"}
{"protocol":"S21","dump":"02473171334E456D03","G1":"q3NE"}
{"protocol":"S21","dump":"0257393D3B78416503","W9":"=;xA"}

[revk]

Those look cleaner!

So maybe we are making progress.

Actually Gq and W9 seem wrong, meaning it may be tx, so yeh, back to what voltage is on pin 1

[revk]

OK weird, return to amazon if faulty - could be a simple component fault.