Permanent VGA Signal Loss when Monitor Disconnected (Mobile 945)

[idata]

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 (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: 04/08/2010Report Time[hr:mm:ss]: 01:12:35Driver Version: 6.14.10.4926Operating System: Windows XP* Professional, Service Pack 3 (5.1.2600)Default Language: EnglishDirectX* Version: 9.0Physical Memory: 1014 MBMinimum Graphics Memory: 8 MBMaximum Graphics Memory: 128 MBGraphics Memory in Use: 11 MBProcessor: x86 family 6 Model 28 Stepping 2Processor Speed: 1599 MHZVendor ID: 8086Device ID: 27AEDevice Revision: 03* Accelerator Information *

Accelerator in Use: Mobile Intel(R) 945 Express Chipset Family

Video BIOS: 1533.0Current Graphics Mode: 1440 by 900 True Color (60 Hz)

* Devices Connected to the Graphics Accelerator *

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

Monitor Name: Plug and Play Monitor

Display Type: AnalogGamma Value: 2.20DDC2 Protocol: SupportedMaximum Image Size: Horizontal: 16.0 inches Vertical: 10.0 inchesMonitor 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 SupportedRaw EDID:00 ff ff ff ff ff ff 00 04 72 4f 00 cd 35 80 9008 13 01 03 68 29 1a 78 ca 80 c5 a6 57 49 9b 2312 50 54 bf ef 80 71 4f 81 40 81 80 81 c0 81 0095 00 95 0f 01 01 9a 29 a0 d0 51 84 22 30 50 9836 00 98 ff 10 00 00 1e 00 00 00 fd 00 38 4c 1f50 0e 00 0a 20 20 20 20 20 20 00 00 00 fc 00 4163 65 72 20 58 31 39 33 57 0a 0a 0a 00 00 00 ff00 4c 44 57 30 44 30 31 36 38 35 30 32 0a 00 a7* Notebook *

Monitor Name: Digital Flat Panel (1280x1024)

Display Type: DigitalGamma Value: 3.54DDC2 Protocol: SupportedMaximum Image Size: Horizontal: Not Available Vertical: Not AvailableMonitor 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.

[idata · Accepted solution]

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: 5/27/2010Report Time[hr:mm:ss]: 13:41:39Driver Version: 6.14.10.5248Operating System: Windows XP Professional Service Pack 3(5.1.2600)Default Language: English (United Kingdom)DirectX* Version: 9.0Physical Memory: 828 MBMinimum Graphics Memory: 128 MBMaximum Graphics Memory: 512 MBGraphics Memory in Use: 32 MBProcessor: x86 Family 6 Model 23 Stepping 6Processor Speed: 2266 MHzVendor ID: 8086Device ID: 2A42Device Revision: 07* Accelerator Information *

Accelerator in Use: Mobile Intel(R) 4 Series Express Chipset Family

Video BIOS: 1704.0Current Graphics Mode: 1024 by 768

* Devices Connected to the Graphics Accelerator *

Active Monitors: 1

Active Notebook Displays: 1 * Monitor *Monitor Name: Plug and Play MonitorDisplay Type: AnalogGamma Value: 2.2DDC2 Protocol: SupportedMaximum Image Size:Horizontal: 14.96 inchesVertical: 11.81 inchesMonitor 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: SupportedSuspend Mode: SupportedActive Off Mode: SupportedRaw 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 MonitorDisplay Type: DigitalGamma Value: 3.55DDC2 Protocol: SupportedMaximum Image Size:Horizontal: Not AvailableVertical: Not AvailableMonitor Supported Modes:1024 by 768 (60 Hz)

Display Power Management Support:

Standby Mode: Not SupportedSuspend Mode: Not SupportedActive Off Mode: SupportedRaw 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 ImageDevice ID: 170Device Revision: 3Major Version: 1Minor Version: 1* Other names and brands are the property of their respective owners. *

[idata]

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.

[idata]

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

[idata]

We contacted our motherboard manufacturer. They Provided us with a http://edc.intel.com/Software/Downloads/IEGD/ IEGD Driver. This solves the problem.