<!DOCTYPE html> <html lang="" xml:lang="" xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"/> <meta content="pandoc" name="generator"/> <meta content="width=device-width, initial-scale=1.0, user-scalable=yes" name="viewport"/> <title>-</title> </head> <body> Folks, a few days ago, my trusted Thinkpad T490 stopped being able to drive an external screen. X thinks it's there, but it doesn't wake up. I have tried all combinations of: <ul> <li>two different monitors </li> <li>two different USB-C docks </li> <li>two different USB-C cables </li> <li>from the docks: DP to DVI, DP to HDMI, VGA </li> <li>HDMI to HDMI on the machine itself</li> </ul> In all of the cases does XRandR recognise the external display properly, and the window manager configures it like I want it to, There is nothing suspicious in Xorg.0.log (attached); in fact, everything seems to be fine there: <pre style="line-height: 125%; margin: 0; padding: 0 1em"><code style="white-space: pre-wrap">(II) intel(0): switch to mode 1920x1080@60.0 on DP2-3 using pipe 1, position (0, 0), rotation normal, reflection none </code></pre> And <code style="white-space: pre-wrap">xrandr</code> thinks the screen is right there: <pre style="line-height: 125%; margin: 0; padding: 0 1em"><code style="white-space: pre-wrap">DP2-3 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 530mm x 300mm 1920x1080 60.00*+ […] </code></pre> But the physical monitor itself just stays suspended / receives no signal. This worked fine forever, until last week, and I have not upgraded the OS (Debian unstable) for weeks, mainly because I've been on the road all the time, and didn't want to risk any breakage. I've verified that the intel video driver hasn't changed in more than a year (2.99.917+git20200714-1+b1), and tried to downgrade both kernel, as well as libdrm-intel1 (to 2.4.104 from 2.4.107) — nothing else has changed on this system, but to no avail. I've tried kernels 5.10.46, 5.10.70, and 5.14.12, which were the ones installed on my system over the last 2 months. I've search the Web, but found very little on this issue, and certainly nothing I have not tried, or that got me anywhere. So right now, I, a heavy multi-screen user who's struggling to get work done using only a single display, is unable to get my external screens to turn on, and I am turning to you for help. What else can I try? Thanks for any help. <div class="signature" style="color: #999; font-family: monospace; white-space: pre; margin: 1em 0 0 0; font-size: 80%">-- @martinkrafft | <a class="uri" href="https://matrix.to/#/#madduck:madduck.net">https://matrix.to/#/#madduck:madduck.net</a> "in just seven days, i can make you a man!" -- the rocky horror picture show spamtraps: <a class="email" href="mailto:madduck.bogus@madduck.net">madduck.bogus@madduck.net</a></div> </body> </html>