Pretty sure this will be a no, but...
We have a 9 year old, very lightly used Mitsubishi standalone dehumidifier that we paid around $750 at the time on special - so not a cheapie.
Haven't used it for a while and plugged it in today and left it running for a while - no moisture being collected and it smells and feels quite warm.
I would guess maybe it needs re-gassing.
Has anyone ever done anything like this and what did it cost?
Or is it just an item for the recycler?