That trick with the mallet is a classic. Saved a few window units that way back when I did apartment maintenance. Some techs just go straight for the most expensive fix.

Tell me about it. My last glue-up turned into a sticky mess that I'm pretty sure is now a science project. Is there a dehumidifier strong enough for a Florida garage?

Felt dry enough" is a killer, I saw a glue-down carpet turn to mush from the same lazy check.