What best use can be made of salvaged boards from an AC unit (heat pump)

[max.wwwang]

See photos for the boards and a high level schematic on its case.

Since there is separate filtering and main switch board (the smaller one), it can be easily be reused. The relays accept 12V DC, not as good as those with standby transformer and accept 5V logic signal (which I salvaged two from AV gear; both used in projects), but it's ok.

The big power chip I believe is a 3 phase inverter module, which is cool but probably difficult to make use of it. (Still have the heatsink that comes with it.)

On the big one, at the very least the full rectifier slice can be reused. Not sure if the part with the uC etc can be reused. In case there is someone who immediately recognises these boards and know them very well?

[Not sure if this (forum) board is the best place for such thing. Moderator feel free to move to wherever you think suits better.]

[jh15]

What went wrong with the heat pump? electronics or compressor, coolant loss, etc?

was the schematic packed in the heat pump? (like the good old days of appliances)

[max.wwwang]

What went wrong with the heat pump? electronics or compressor, coolant loss, etc?

was the schematic packed in the heat pump? (like the good old days of appliances)

No idea whatsoever.  No more detailed schematics.

[max.wwwang]

Tested with the big one by connecting to mains, and with a DMM hooked (voltage) across the big ass caps. Apparently at least the rectifier filtering stage is working however it immediately tripped the mains switchboard. I suspect it was due to the installation current surge. Then I added an incandescent bulb in series and this time it was fine. The little led on the board lit up.

If I hook the small board up, which has the massive what I understand are common mode chokes, and again based on my understanding of these chokes, they will have no effect in smoothing the momentary current inrush when turned on. This makes me wonder why other SMPSs don’t trip the switchboard given they all have essential the same rectifier and massive caps filtering stage upfront?

Is it just because the capacity of the capacitors of this one (620uF x 3, which is not terribly enormous)? Not likely shorted because if so, I would have been the diodes that suffered.