I have the following hardware:
Primary display - HP Touchsmart 520-1085uk running Win7
Secondary display - HP L1908W on DVI/VGA cable via plugable USB 2.0 to UGA adapter
Tertiary display - LG Flatron L1718S on VGA/VGA cable via plugable USB 2.0 UGA adapter
Both monitors/UGA adapters have individual USB 2.0 ports (i.e not hub’d).
- Unable to display 2nd and 3rd monitors at any on time.
- If the 2nd monitor is working, the 3rd will not display, however, if i unplug the 2nd monitor USB, the 3rd will activate and display correctly.
- Both USB 2.0/UGA adapters are showing blue lights and have been proven to work individually.
- 2 x Video display adapters are visible in the installed devices (device mgr)
- Displaylink S/W is installed correctly.
- The HP 520 has a Radeon 6550A graphics card.
- WDP will not detect a new monitor even thought it is connected.
- Displaylink S/W and driver is up to date.
- There are 3 places where display properties can be modified: WDP, Displaylink and the AMD Catalyst S/W.
- Windows services - there is 1 instance of DisplayLinkService
- Windows processes - there is 1 instance of DisplayLinkManager.exe, DisplayLinkUI.exe and DisplayLinkUserAgent.exe
Please could you provide advice/solution for this issue. It seems to me that the USB bus only ever sees/allows active use of 1 adapter at a time,
almost like there is contention between the 2, 1 of the adapters takes precedence and if the active port is disconnected the other takes control of USB.