Wrong Screen resolution - lost use of monitor even on rebooting

[newtusmaximus]

Agree have to stick with solving this as others may suffer this problem in the future.
So
a) Boot up - on switch, stabbing continuously on escape key - brings up GRUB screen
b) highlighting linux 4.4.0-71 generic press "e" key and into edit mode.  Insert "nomodeset"  in the correct line as per the link in previous post and then press F10.
c) turned off monitor until all boot up activity settled and then turned on monitor again.
d) Login flash screen displayed. Logged in
e) Sound and screen displays welcoming page - however display very large -
f) menu/settings/display  shows "default"  set at 640 x 480  .  This can not be changed  closed.
g) Terminal xrandr -s 1024x768  still states can't be accessed.
h) Back to main screen and close down via screen
i) Wait for a few minutes then reboot with screen off, wait until boot activity has quietened down, turn screen on and login screen displayed - login  and  x/y oscillations recur.  i.e nomodeset  and subsequent stab at changing display settings via menu has not worked.