[HELP] No monitor device in Vista Device Manager

renda

My laptop is an old model (ECS/EliteGroup G420) but Vista-32 can run very well on it. The ATI Mobility Radeon X1300 adapter can be detected with no problem, but the default LCD panel does not appear in the device manager (even no monitor branch).

This won't be a problem if I don't have to connect a projector to make presentations to my clients, since everything is normal (including Aero Glass feature) when the main LCD panel is used as the only display. Vista can also correctly detect the LCD's native resolution (1280x800).

But unfortunately presentation is a big part of my job. What made me really pained is whenever a projector or an external monitor is connected, the main LCD panel will lose signal (I mean it's completely blacked out, even no back-light). I have to locate the moving mouse arrow on the projector screen from 20 feet away, and the only way to get the main LCD back to work is to reboot!!! That damnly sucks!!!

I suspect the reason for this problem is, when an external monitor is detected, the adapter driver considers the external moniter as the only one attached to the computer and no more outputs to the LCD.

Since the laptop manufacturer does not provide Vista driver for this model, I have to look for a working one by myself. However I've tried many (not less than 10) versions from ATI and other sources, I am still not able to find a work around.

What I've tried includes:

• ATI official driver 8.4 (and 8.3.1) for Vista-32 + HydraVision: the default LCD panel is shown as "disabled" in display manager.
• The WDDM compliant one included in Vista installation disc (which has a version number 7.6)
• Dell/IBM/ASUS driver 8.3.1 for Vista-32 (provided for their earlier products w/ Mobility Radeon X1300)
• ATI official driver 8.4 + DH Mobility Modder .Net v4
• Ray Adam's ATI Tray Tool (tried with some advanced display tweaks)
• ECS EliteGroup original driver for XP: after I just installed this driver, Vista DID detect the default LCD monitor, but after the next reboot, it disappeared again (I also heard an alert sound indicating device disconnected).
• PowerStrip
• ....
• I didn't try the Omega driver since there's no Vista version available, and I love the Aero Glass appearance which is not available when an XP driver is used.

I am not sure if this issue is caused by the LCD hardware, which seems not to be able to work with DCC/CI mechanism (when I tried to read EDID data directly from the monitor with PowerStrip I got a "DCC communication error". I knew little about WDDM but I just suppose this may prevent Vista from detecting the LCD as a valid monitor.

BTW, in Vista registry there are several subkeys under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\D ISPLAY\TNJ0260, listed as below:

• 5&2fa4a0b&0&10000081&01&00
• 5&5f175a9&0&10000081&01&00
• 5&5f175a9&0&12345678&01&00
• 5&5f175a9&0&UID268435456
• 5&5f175a9&1&10000081&01&00
• 5&5f175a9&1&UID268435456
• 5&5f175a9&2&12345678&01&00

Each of the above subkeys has a 2nd-level subkey named "Device Parameters", which contains an REG_BINARY type value named EDID. All of those value are same, I can locate the model and manufacturer info from the binary data, which read: TD141THCA1 (model) and TOPPOLY (manufacturer). But I don't know why Vista does not treat it a valid monitor device while it can read the correct EDID data into the registry.

It has been days since this issue harassed me badly, anyone can point me a work around on this? I would gratefully appreciate your favor!!!

temeteus82

Thread Closed!

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