Hello, I seem to be having an increasing problem on my Thinkpad Carbon X1 2015, where: * The screen will lose sync. Like it is an older analogue monitor. Sometimes it will come good after 1 second. Other times a suspend/resume will solve this. Some videos showing the problems: https://photos.app.goo.gl/g71psLYXEfcNK1Vx1 - the black screen with dots is uncommon, the scrolling display is more common. This is with *one* emacs window shown at full screen. * The screen will flash bright for a second, go back to normal, and then the computer will completely freeze. * These above symptoms typically happen in response to a keypress at a terminal window (gnome terminal and xterm both affected). Especially the down button or escape key, but these aren't the only ones. Happens with no external devices plugged in. * wayland/xorg gnome/kde/awesome/etc all have the same problem. Have latest Debian/stretch with latest security updates. It is possible that a regression in a security update has caused increased problems, but I am doubtful. At first I thought this was a hardware problem. Which means I should try to get it fixed under warranty. But: * Built in tests all pass. * The problem is not reproducible under Windows. * I installed Debian/stretch (brand new install) on a very different computer - a MacBook Pro, and encounter - what appears to be - exactly the same symptoms. Although the "lost sync" affect doesn't last as long. The only thing in common is both have high resolution displays. I reduced the resolution on the Thinkpad, just in case, but still get similar problems. This MacBook Pro works fine with OSX. Any ideas? This is making Linux on these computers unusable, I never know when it is going to crash. In practice, times are often very short, or worst time (e.g. 2nd time entering this email... This time under OSX). Regards