4 Replies Latest reply on Jun 7, 2010 2:51 AM by david.bleakley

    Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)

    SWi

      I'm running a single-board computer (x86, XP SP3) that uses a Mobile 945 as its graphics processor.  There are two displays available: One VGA and one DFP.  The DFP is implemented by the board's manufacturer, but it is not accessible by us.

       

      The basic problem is that our customers may not normally have a (VGA) monitor connected.  That is only necessary for configuration and troubleshooting.  What we find is that if the system boots without the monitor connected or even if we disconnect the monitor after the system is running, when we reconnect the monitor it remains black.  It appears as if the graphics subsystem does not detect its presence.

       

      Naturally, we want to find a way to always keep the VGA port alive (or at least have it enable when a monitor is connected).

       

      Device Manager shows two display adapters and five monitors (two DFP and three VGA).  This appears to be normal.

       

      We have tried the following approaches to solving this problem.  None of them work:

       

      - Using hotkeys (<CNTL><ALT>1) to enable the monitor after it is (re-)connected

      - Disabling all the DFP's in Device Manager (we even tried disabling one of the display adapters)

       

      We had some success when we configured the driver for Multiple Display/Intel(R) Dual Display Clone.  In this setup, we can disconnect the monitor and the VGA output is active when we reconnect.  The problem is that this configuration does not persist after a reboot (the system reverts to the single-monitor configuration).  One other annoyance is that the graphics driver will not allow us to select the native resolution of the monitor.  It appears to force both VGA and DFP to use the same resolution (which makes sense in this case).

       

      Attempting to force the desired mode by editing the registry does not work.  The system seems to reject the new values.

       

      Is there a set of registry modifications or an application that we can auto-run at startup that will solve this problem?  It would be ideal if the application that configures the driver (igfxcfg.exe) could be run with command-line arguments that would set the desired configuration.  We could set up a "scheme" with the desired options and invoke that.

       

      Here is the output generated by the graphics driver utility:

       

      Intel(R) Graphics Media Accelerator Driver for Mobile Report


      Report Date:  04/08/2010
      Report Time[hr:mm:ss]: 01:12:35
      Driver Version:  6.14.10.4926
      Operating System:  Windows XP* Professional, Service Pack 3 (5.1.2600)
      Default Language:  English
      DirectX* Version:  9.0
      Physical Memory:  1014 MB
      Minimum Graphics Memory: 8 MB
      Maximum Graphics Memory: 128 MB
      Graphics Memory in Use: 11 MB
      Processor:  x86 family 6 Model 28 Stepping 2
      Processor Speed:  1599 MHZ
      Vendor ID:  8086
      Device ID:  27AE
      Device Revision:  03


      *   Accelerator Information   *

      Accelerator in Use:  Mobile Intel(R) 945 Express Chipset Family
      Video BIOS:  1533.0
      Current Graphics Mode: 1440 by 900 True Color (60 Hz)

       

      *   Devices Connected to the Graphics Accelerator   *


      Active Monitors: 1
      Non Active Notebook Displays: 1


      *   Monitor   *

      Monitor Name:  Plug and Play Monitor
      Display Type:  Analog
      Gamma Value:  2.20
      DDC2 Protocol:  Supported
      Maximum Image Size: Horizontal: 16.0  inches
         Vertical:   10.0  inches
      Monitor Supported Modes:
      640 by 480 (60 Hz)
      640 by 480 (67 Hz)
      640 by 480 (72 Hz)
      640 by 480 (75 Hz)
      720 by 400 (70 Hz)
      800 by 600 (56 Hz)
      800 by 600 (60 Hz)
      800 by 600 (72 Hz)
      800 by 600 (75 Hz)
      832 by 624 (75 Hz)
      1024 by 768 (60 Hz)
      1024 by 768 (70 Hz)
      1024 by 768 (75 Hz)
      1152 by 864 (75 Hz)
      1152 by 870 (75 Hz)
      1280 by 720 (60 Hz)
      1280 by 960 (60 Hz)
      1280 by 1024 (60 Hz)
      1280 by 1024 (75 Hz)
      1280 by 1280 (60 Hz)
      1440 by 900 (60 Hz)
      1440 by 1440 (60 Hz)
      1440 by 1440 (75 Hz)
      Display Power Management Support:
      Standby Mode: Supported
      Suspend Mode: Supported
      Active Off Mode: Not Supported
      Raw EDID:
      00 ff ff ff ff ff ff 00 04 72 4f 00 cd 35 80 90
      08 13 01 03 68 29 1a 78 ca 80 c5 a6 57 49 9b 23
      12 50 54 bf ef 80 71 4f 81 40 81 80 81 c0 81 00
      95 00 95 0f 01 01 9a 29 a0 d0 51 84 22 30 50 98
      36 00 98 ff 10 00 00 1e 00 00 00 fd 00 38 4c 1f
      50 0e 00 0a 20 20 20 20 20 20 00 00 00 fc 00 41
      63 65 72 20 58 31 39 33 57 0a 0a 0a 00 00 00 ff
      00 4c 44 57 30 44 30 31 36 38 35 30 32 0a 00 a7


      *   Notebook   *

      Monitor Name:  Digital Flat Panel (1280x1024)
      Display Type:  Digital
      Gamma Value:  3.54
      DDC2 Protocol:  Supported
      Maximum Image Size: Horizontal: Not Available
         Vertical:   Not Available
      Monitor Supported Modes:
      1280 by 1024 (60 Hz)
      Display Power Management Support:
      Standby Mode: Not Supported
      Suspend Mode: Not Supported
      Active Off Mode: Supported

      * Other names and brands are the property of their respective owners.                                                                                                                                                                                             

        • 1. Re: Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)
          david.bleakley

          I have the same problem with a single-board computer (x86, XP SP3) that uses a GM45 chipset. Have you had any luck with this?

           

          Intel® Graphics Media Accelerator Driver for Mobile Report


          Report Date:            5/27/2010
          Report Time[hr:mm:ss]:        13:41:39
          Driver Version:            6.14.10.5248
          Operating System:        Windows XP Professional Service Pack 3(5.1.2600)
          Default Language:        English (United Kingdom)
          DirectX* Version:        9.0
          Physical Memory:        828 MB
          Minimum Graphics Memory:    128 MB
          Maximum Graphics Memory:    512 MB
          Graphics Memory in Use:        32 MB
          Processor:            x86 Family 6 Model 23 Stepping 6
          Processor Speed:        2266 MHz
          Vendor ID:            8086
          Device ID:            2A42
          Device Revision:        07


          *   Accelerator Information   *

           

          Accelerator in Use:        Mobile Intel(R) 4 Series Express Chipset Family
          Video BIOS:            1704.0
          Current Graphics Mode:        1024 by 768

           

          *   Devices Connected to the Graphics Accelerator   *

          Active Monitors: 1
          Active Notebook Displays: 1
              *    Monitor    *

           


          Monitor Name:            Plug and Play Monitor
          Display Type:            Analog
          Gamma Value:            2.2
          DDC2 Protocol:            Supported

           


          Maximum Image Size:
          Horizontal:            14.96 inches
          Vertical:            11.81 inches

           


          Monitor Supported Modes:
          640 by 480 (67 Hz)
          640 by 480 (72 Hz)
          640 by 480 (75 Hz)
          640 by 480 (60 Hz)
          720 by 400 (70 Hz)
          800 by 600 (72 Hz)
          800 by 600 (75 Hz)
          800 by 600 (56 Hz)
          800 by 600 (60 Hz)
          832 by 624 (75 Hz)
          1024 by 768 (75 Hz)
          1024 by 768 (70 Hz)
          1024 by 768 (60 Hz)
          1152 by 864 (75 Hz)
          1152 by 870 (75 Hz)
          1280 by 960 (75 Hz)
          1280 by 1024 (75 Hz)
          1280 by 1024 (60 Hz)
          1280 by 960 (60 Hz)

           

           

           

          Display Power Management Support:
          Standby Mode:            Supported
          Suspend Mode:            Supported
          Active Off Mode:        Supported

           


          Raw EDID:
          00 FF FF FF FF FF FF 00 15 C3 32 18 01 01 01 01
          19 11 01 03 68 26 1E 78 EA E4 15 A3 54 4A 9B 25
          13 50 54 BF EF 80 81 80 81 40 81 4F 71 4F 01 01
          01 01 01 01 01 01 30 2A 00 98 51 00 2A 40 30 70
          13 00 78 2D 11 00 00 1E 00 00 00 FF 00 48 32 38
          39 30 30 36 37 0A 20 20 20 20 00 00 00 FD 00 32
          4B 18 50 0E 00 0A 20 20 20 20 20 20 00 00 00 FC
          00 53 31 39 32 31 0A 20 20 20 20 20 20 20 00 36

           

              *    Built-in Display    *


          Monitor Name:            Plug and Play Monitor
          Display Type:            Digital
          Gamma Value:            3.55
          DDC2 Protocol:            Supported


          Maximum Image Size:
          Horizontal:            Not Available
          Vertical:            Not Available


          Monitor Supported Modes:
          1024 by 768 (60 Hz)

           

          Display Power Management Support:
          Standby Mode:            Not Supported
          Suspend Mode:            Not Supported
          Active Off Mode:        Supported

           


          Raw EDID:
          00 FF FF FF FF FF FF 00 36 7F 04 90 09 00 00 00
          00 0C 01 03 80 00 00 FF 2F 00 00 A0 57 49 9B 26
          10 48 4F 00 00 00 01 01 01 01 01 01 01 01 01 01
          01 01 01 01 01 01 64 19 00 40 41 00 26 30 18 88
          36 00 00 00 00 00 00 18 00 00 00 FD 00 00 3C 00
          EB 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00
          00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
          00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 D1

           


          *        SDVO Encoder Report        *


          ** Encoder 1 **
          Vendor ID:            Silicon Image
          Device ID:            170
          Device Revision:        3
          Major Version:            1
          Minor Version:            1
          * Other names and brands are the property of their respective owners. *

          • 2. Re: Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)
            SWi

            We were not able to find a solution on our own.  We appealed to the manufacturer of the CPU module we use and they modified the BIOS.  They didn't provide details of what they changed, but the problem has been fixed.  I do think that a BIOS change is the only way to handle this problem.  Intel does not provide any details of the internals of their drivers (much less the actual source code), so we are pretty much at the mercy of whatever behaviour is intrinsic to the BIOS/driver combination.

            • 3. Re: Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)
              david.bleakley

              Thank you. We are currently having our bios defaults set. Hopefully the CPU board manufacturer can solve this too.

              • 4. Re: Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)
                david.bleakley

                We contacted our motherboard manufacturer. They Provided us with a IEGD Driver. This solves the problem.