DisplayLink Forum - View Single Post - Switching away and back to my Mac via VKM disables the DisplayLink monitor.

EdF · 06-01-2012, 12:19 AM

I have a MacMini (Mid 2007) with my primary monitor hooked up to the internal display port, and a 2nd monitor hooked up to a DisplayLink BVU195 USB adapter.

Both of the monitors (and a keyboard/mouse) are shared between this Mac and a PC via an IoGear GCS1744 KVM.

Previously, it all worked perfectly under OSX 10.6.8 (Snow Leopard) with DisplayLink 1.7b4 drivers. I was able to switch back and forth between the systems as I needed.

Today I updated to OSX 10.7.4 (Lion) and DisplayLink 1.8a1 drivers. When the Mac boots, the 2nd display seems fine. However, when I switch away from the Mac to the PC, and then switch back to the Mac, the Mac seems to think the second monitor has gone away. The monitor displays black, and I can't move the mouse cursor over to it, (so it's not like the Mac thinks the display is there and the monitor is just showing black- the Mac now acts like a single-monitor system.) The green LED on the DisplayLink adapter is lit the whole time, even after switching back to the Mac. This happens 100% of the time.

Here's the really weird thing (IMHO): Once it gets into this state, if I unplug the DisplayLink adapter from it's USB port and re-insert it, the Mac will then detect the DisplayLink and second monitor. Now I can switch back and forth between the Mac and PC at will again with the second monitor working fine!

UNTIL I reboot the Mac, and then I need to unplug and re-plug the DisplayLink USB again to make the second monitor "stick" again through the KVM switchouts!

I downgraded the DisplayLink drivers back to 1.7, and then back to 1.7b4 and the problem happens with all three of these DisplayLink driver versions.

Is this a known issue with OSX Lion and the DisplayLink?
Has anyone else seen behaviour like this on a Mac via KVM switch?
Is there more info I can provide?

Thanks for any info, tips, or suggestions.

06-01-2012, 12:19 AM	#1
EdF Junior Member Join Date: May 2012 Posts: 2	Switching away and back to my Mac via VKM disables the DisplayLink monitor. I have a MacMini (Mid 2007) with my primary monitor hooked up to the internal display port, and a 2nd monitor hooked up to a DisplayLink BVU195 USB adapter. Both of the monitors (and a keyboard/mouse) are shared between this Mac and a PC via an IoGear GCS1744 KVM. Previously, it all worked perfectly under OSX 10.6.8 (Snow Leopard) with DisplayLink 1.7b4 drivers. I was able to switch back and forth between the systems as I needed. Today I updated to OSX 10.7.4 (Lion) and DisplayLink 1.8a1 drivers. When the Mac boots, the 2nd display seems fine. However, when I switch away from the Mac to the PC, and then switch back to the Mac, the Mac seems to think the second monitor has gone away. The monitor displays black, and I can't move the mouse cursor over to it, (so it's not like the Mac thinks the display is there and the monitor is just showing black- the Mac now acts like a single-monitor system.) The green LED on the DisplayLink adapter is lit the whole time, even after switching back to the Mac. This happens 100% of the time. Here's the really weird thing (IMHO): Once it gets into this state, if I unplug the DisplayLink adapter from it's USB port and re-insert it, the Mac will then detect the DisplayLink and second monitor. Now I can switch back and forth between the Mac and PC at will again with the second monitor working fine! UNTIL I reboot the Mac, and then I need to unplug and re-plug the DisplayLink USB again to make the second monitor "stick" again through the KVM switchouts! I downgraded the DisplayLink drivers back to 1.7, and then back to 1.7b4 and the problem happens with all three of these DisplayLink driver versions. Is this a known issue with OSX Lion and the DisplayLink? Has anyone else seen behaviour like this on a Mac via KVM switch? Is there more info I can provide? Thanks for any info, tips, or suggestions.