Recently I found already running VNC landed with blank screen out of the moon. Debugging revealed after uninstalling some packages related with Window/Desktop managers, existing xstartup of VNC failed to call Desktop manager. Experienced frequently with Gnome. My VNC again came back to life with below xstartup which instructs VNC to call DM explicitly.
#!/bin/sh # Uncomment the following two lines for normal desktop #Helpful to get just simple gnome unset SESSION_MANAGER exec /etc/X11/xinit/xinitrc [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources xsetroot -solid grey vncconfig -iconic & #set the geometry as per requirement xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & #call DM #twm& #icewm& gnome-session&