AppleColor RGB monitor: working or not?

[sqlman <none@abc.xyz>]

I got an AppleColor monitor for Apple IIgs, but I have no computer to
test it.  When I turn it on, it powers up with a distinct sound of
discharge (?) like Trinitron monitors do, and stays on.  What
surprises me is that the screen remains completely dark, like in "off"
mode, no difference. Adjusting brightness or contrast does not make
the screen lit up a single bit. Is this normal?  I would expect any
CRT monitor to lit up somewhat when not connected to a computer,
especially when maxing out the brightness.

Huh?