USB-C video problems
Posted: Thu Aug 31, 2023 4:25 am
I have a universal ThinkPad USB-C Dock (40A9)
-the dock is powered by 135W lenovo ac adapter (yellow port on the left)
-a dell monitor is connected using a DP cable from the dock
-mouse and keyboard are on a KVM which interfaces to the dock via USB
the above setup works just fine using my work laptop, a lenovo T490 with a USB-C cable connecting the laptop and the dock. However, when i tried that with AMR5 5800U by connecting the USB-C cable to the front of AMR5 and the dock (between power port and VGA) it gets as far as showing the desktop and then a few seconds later the AMR5 powers off. I tried two different cables that work with the laptop with the same result.
-when i connect the DC19V brick and use USB-C as video out, same thing happens and the machine shuts down.
-USB-C as power/hub and DP as video out - crash
+when i connect the DC19V brick, unplug DisplayPort from the dock and plug it in directly to the back of AMR5, leaving USB-C plugged in (essentially as a glorified hub) everything is ok
latest windows updates and drivers applied and i'm stuck. no USB-C monitor to try that directly without a dock and no other dongles/adapters i have handy. any ideas on what else to troubleshoot? any specific BIOS settings? i've reset it to defaults already and no change
it doesn't matter which GFX option it's set to except i haven't tried 'disabled'
when on DP directly it's as pictured below when display is via USB-C it changes to DFP1_DP i think - not sure if that makes any difference
safe mode without networking was ok on one occasion but another time it crashed so that's inconclusive
come to think of it, it never crashes in the BIOS, so i'm leaning to drivers or some programs/services that start in windows?
it's a bare bones installation as i was just doing some stability testing and tweaking W10 (passmark, furmark, cinebench, prime95 etc. all worked flawlessly when USB-C was not used.
I might try a clean install and start everything via USB-C but that's last resort for now so if you have any ideas i'm all ears!
-the dock is powered by 135W lenovo ac adapter (yellow port on the left)
-a dell monitor is connected using a DP cable from the dock
-mouse and keyboard are on a KVM which interfaces to the dock via USB
the above setup works just fine using my work laptop, a lenovo T490 with a USB-C cable connecting the laptop and the dock. However, when i tried that with AMR5 5800U by connecting the USB-C cable to the front of AMR5 and the dock (between power port and VGA) it gets as far as showing the desktop and then a few seconds later the AMR5 powers off. I tried two different cables that work with the laptop with the same result.
-when i connect the DC19V brick and use USB-C as video out, same thing happens and the machine shuts down.
-USB-C as power/hub and DP as video out - crash
+when i connect the DC19V brick, unplug DisplayPort from the dock and plug it in directly to the back of AMR5, leaving USB-C plugged in (essentially as a glorified hub) everything is ok
latest windows updates and drivers applied and i'm stuck. no USB-C monitor to try that directly without a dock and no other dongles/adapters i have handy. any ideas on what else to troubleshoot? any specific BIOS settings? i've reset it to defaults already and no change
it doesn't matter which GFX option it's set to except i haven't tried 'disabled'
when on DP directly it's as pictured below when display is via USB-C it changes to DFP1_DP i think - not sure if that makes any difference
safe mode without networking was ok on one occasion but another time it crashed so that's inconclusive
come to think of it, it never crashes in the BIOS, so i'm leaning to drivers or some programs/services that start in windows?
it's a bare bones installation as i was just doing some stability testing and tweaking W10 (passmark, furmark, cinebench, prime95 etc. all worked flawlessly when USB-C was not used.
I might try a clean install and start everything via USB-C but that's last resort for now so if you have any ideas i'm all ears!