Monitor change: Change frequencies at boot time

["JB MORLA" <jbmorla@gmail.com>]

Hi,

 

My Debian displays on an old 15" Cathodic MaCom Monitor.

I plan to change it for a budget 19" Samtron.

Obviously I have to modify the Horizontal sync and Vertical refresh hz in /etc/X11/XF86Config-4

When do I do that? Before or after changing the monitor?

How long do I have before it fries if the Hz aren't ok?

 

Hints and Advice wanted and welcome!

 

Jean-Benoit