Ubuntu 15.04 第二個顯示器空白且 LED 閃爍

Question

我有一張帶有 3 個 DVI 輸出的 VisionTek Radeon 卡。我已使用適配器將其中一個連接到 DVI 顯示器，將第二個連接到 VGA 顯示器。兩者都會顯示在設定|顯示和 Catalyst 中，但 VGA 始終為空白且 LED 閃爍。

Screen 0: minimum 320 x 200, current 3200 x 1080, maximum 8192 x 8192
      DFP1 connected 1280x768+1920+0 (normal left inverted right x axis y axis) 477mm x 268mm
         1280x768      59.81*+
         1920x1080     60.00 +
         1680x1050     60.00  
         1400x1050     60.00  
         1600x900      60.00  
         1360x1024     60.00  
         1280x1024     60.02  
         1440x900      59.89  
         1280x960      60.02  
         1280x800      59.81  
         1152x864      60.00    75.00  
         1280x720      59.81  
         1024x768      70.07    60.00  
         800x600       60.32    56.25  
         640x480       67.00    59.94  
      DFP2 disconnected (normal left inverted right x axis y axis)
      DFP3 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm
         1920x1080     60.00*+
         1680x1050     59.95  
         1400x1050     59.95  
         1600x900      59.95  
         1360x1024     59.95  
         1280x1024     60.02  
         1440x900      59.89  
         1280x960      60.02  
         1280x800      59.81  
         1152x864      60.00    75.00  
         1280x768      59.81  
         1280x720      59.86  
         1024x768      70.07    60.00  
         800x600       60.32    56.25  
         640x480       66.61    59.94  

關於我配置錯誤的任何想法？