Update: UltraVNC 1.4.3.6 and UltraVNC SC 1.4.3.6: viewtopic.php?t=37885
Important: Please update to latest version before to create a reply, a topic or an issue: viewtopic.php?t=37864

Join us on social networks and share our announcements:
- Website: https://uvnc.com/
- GitHub: https://github.com/ultravnc
- Mastodon: https://mastodon.social/@ultravnc
- Facebook: https://www.facebook.com/ultravnc1
- X/Twitter: https://twitter.com/ultravnc1
- Reddit community: https://www.reddit.com/r/ultravnc
- OpenHub: https://openhub.net/p/ultravnc

Windows 10 Screen Freezes when Lid is Closed

Post Reply
AaronD
Posts: 2
Joined: 2016-11-30 23:51

Windows 10 Screen Freezes when Lid is Closed

Post by AaronD »

I discovered this while DJ'ing a wedding reception. I was supposed to have a Banana Pi running a remote-controllable media player on stage while I sat in the audience with a netbook. But the media player didn't work in time so I loaded up the music in my Windows 10 laptop and set it on stage instead with the lid closed, using uVNC to control it graphically.

Not having sufficient time to test this setup fully, I found out live that I could still control the laptop - that is, mouse and keyboard events still had the desired effect - but the display remained frozen. So I was mostly flying blind and therefore couldn't take requests. I could, however, use the play/pause, prev, next, shuffle, and repeat buttons and change playlists because they never moved from the original screenshot.

At the very end, I just happened to figure out that if I left the lid open (with kids around :shock: ), then I got live video and could therefore do anything I wanted.

I hope I don't get into that situation again (still working on the BPi player), but I'm still curious as to why the uVNC server wouldn't update the display with the lid closed and Windows 10 set to do nothing.
User avatar
Rudi De Vos
Admin & Developer
Admin & Developer
Posts: 6832
Joined: 2004-04-23 10:21
Contact:

Re: Windows 10 Screen Freezes when Lid is Closed

Post by Rudi De Vos »

Closing the laptop put the video card in a power down state.
Vnc clone the real screen, and when there is no screen, you can't clone anything.

You can tell a laptop that a vga monitor is connected ( most video cards have the option to overwrite the detection)
In that setup, even with a closed cover, the video keeps working.
AaronD
Posts: 2
Joined: 2016-11-30 23:51

Re: Windows 10 Screen Freezes when Lid is Closed

Post by AaronD »

Okay, that makes sense. So there's really nothing wrong with uVNC or its configuration, and in fact it's still doing all it can (mouse and keyboard still work), but it just doesn't have anything to work with anymore in regard to video. Or more accurately, the power down state just stopped updating the buffer and left it as it was while the server kept reading it. That also explains the connection staying up and perhaps even a small part of the screen that actually would update (preview window of a virtual machine, far too small to be useful) because it was drawn differently than the rest (maybe explicitly by the CPU instead of by the video card).

Thanks Rudi!
Post Reply