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absalom-muc / MHI-AC-Ctrl

Reads and writes data (e.g. power, mode, fan status etc.) from/to a Mitsubishi Heavy Industries (MHI) air conditioner (AC) via SPI controlled by MQTT
MIT License
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How to test for faulty HW components? #179

Closed Kurisutian closed 5 months ago

Kurisutian commented 5 months ago

Currently I have some kind of weird problem: The adapter was running fine for a while but suddenly the AC is just dead. I take off the device and power it back on and everything works. I did check everything as far as my knowledge allowed. Components seem to be fine, soldering does not seem to be off as well (it worked anyways for a while). So how can I find out why the device suddenly refused to work? It was fine all summer long and a second one still is fine on the 2nd AC. However I have this weird situation that 4 out of 6 devices do not seem to last in the beginning with the 5th one suddenly not working after one summer. Is there any way I can test the individual parts? I checked also by switching off the fuse and waiting but no matter what I do not get it back online. I checked my network logs and the device was definitely working but suddenly it started disappearing and coming back just to be completely offline and keeping the AC unit from powering up. For now I will remove it to at least get the AC working but rather than building 10 devices hoping to get one more to keep working I would love to find out what I did wrong eventually or what component might be from a faulty series as like I described I did experience with the majority of the devices I built.

Is there anything like that known so I do get a starting point where to look at?

glsf91 commented 5 months ago

Start by connecting the module to your PC with an usb cable and monitor the logging on this seral port.

You can also measure if the TSR_1-2450 is still supplying 5V.

Kurisutian commented 5 months ago

Somehow the device started working again after 2 or 3 days... somebody suspected the level shifter being a possible cause. I will keep an eye on it. As there is no reason to test any longer, I will close this one. Thanks!