Hi guys. I have an Amstrad 1640ECD. The monitor internally is in perfect condition and I have changed all the electrolytic capacitors. The problem I have is that I can not adjust the horizontal screen size to 350 lines resolution. At a resolution of 200 lines the monitor shows correctly. The monitor internally has sliders for the vertical position and the vertical size but not for the horizontal one. You can see the problem in the images below (norton commander - Text app) Any suggestions?