In my opinion - as long as you list / sell the machine as not working then I wouldn't think this is unethical at all.

I prefer to buy machines not working, that way it gives me a chance to fully strip and rebuild all components.

You should be enjoying your games, not giving you a headache.  You've had more patience with this game than I would have had!

If it helps contribute towards a JP - being a dream pin for you then I'd do it.