After a long time, I had managed to do an almost 2 full hour long session today.

Here’s what I did for today:
Successfully reseated the fuse.
Put the inverter board back into its enclosure
Took it out since I forgot to mount the TO220 package components on their metal heatsink.
Put it back into its enclosure.
Noticed that the screw was touching the heatsink, which might cause issues.
Pulled it out again, bent the sheet a little and bent it too much, making virtually no contact with a MOSFET. Took it all out, bent the sheet back, spent another 10 minutes looking for the orientation, and finally secured it very firmly.
Had to be gentle during the assembly and yet I broke a screw peg and did a temporary, caveman plastic welding.
Like always, I was ranting about the repairability of this portable power station in my mind.

Now I’m seeing another issue (not another -_-):
The down arrow button doesn’t work. It worked intermittently for a bit while assembling but now it is completely dysfunctional. Need to diagnose this tomorrow