Z Carriage Dropsy

When powering on my Mini 2, the Z carriage drops. Is this symptomatic of loose bearings?
Started after printing at high polycarbonate temps.
Vid:
https://www.dropbox.com/s/mh4i2n21t1nfk8v/IMG_2848.TRIM.MOV?dl=0

That’s a different behavior than we’d expect. Send this video and more information on your setup for your polycarbonate prints to https://LulzBot.com/Support.

So, support thinks it’s a bad Z Brake Board.($50)
Other than undesirable behavior, doesn’t seem to be causing any other problems… Is it necessary?

As long as a freshly printed object isn’t in danger of having the hot nozzle dropped onto it because the brake is bad…