T42 14.1" 1400x1050: Not Plug'n'Play, no DDC/CI or EDID

[RolfThinkPad]

T42 14.1" 1400x1050: Not Plug'n'Play, no DDC/CI or EDID

After a clean install of Win7, the monitor is listed in Device Manager as Generic NON Plug and Play.
So the default non-PnP monitor driver is loaded.
Further investigation in the registry and various monitor software tools show that the monitor does not report an EDID and does not have DDC/CI support. This explains the behaviour above.

This must be why the video driver always defaults to a low refresh rate and sub-optimal settings - it is looking for DDC and an EDID and there isn't one!

All mentioned above dispappears when an external monitor is attached - there is an EDID, DDC is supported, the monitor is PnP and the video driver is fine with it all. This proves that the video driver works when presented with a PnP monitor.

Q. Can anyone explain why the T42 14.1" 1400x1050 monitor does not support DDC/CI and has no EDID? I find this most bizarre and it is causing visible problems because the driver is stuck in suboptimal settings that can't be altered.

I have tried loading a modified EDID into the registry, but the video driver ignores it (and everything else I try). There are no errors or unknown devices in device manager and Win7 runs fine otherwise.

Please help!

[ajkula66]

Most of T42 LCDs do not have an EDID chip to begin with...

[RolfThinkPad]

Wow! If that is the case it would explain almost everything.
I'll look into solving this with this new piece of valuable info.
Thanks.

[GACrabill]

What is your 'Display adapter' driver version from Device Manager ?

The "one that works" with Win7 T40-T42 models with ATI 7500 or ATI 9000 graphics chips is "6.14.10.6606".

[RolfThinkPad]

Been through every version I could find and the only one that "works" is the latest XP one provided by IBM, namely 6.14.10.6547

But this has other big issues with Windows 7 when it comes to docking stations, multiple moniters, etc.
There is another thread on the subject of Win7 and drivers for the Radeon Mobility 9600 I have.

I raised this new thread to get info on the fact there is no EDID.

Now I'm almost giving up because I tried an EDID override for the LCD in question, and it installed fine. But the video driver just ignores it. This should not happen, as EDID overrides are valid for Windows 7, according to Microsoft.

Now attempting to decipher the ATI registry keys and the installation files to see if monitor settings can be set properly.
As I said, i know the Win7 ATI video driver works fine for the external monitor, so it is caable of providing proper settings.

Anyway, any info on the EDID / PnP issue will still be welcome.

[ajkula66]

Have you tried uninstalling the XP driver and allowing W7 to find the video driver for the ATi card?

[RolfThinkPad]

I gave up.

I tried everything, and spent huge amounts of time on it.

Also got hold of the Windows 7 driver as instructed and provided by Microshaft, and tried altering the INF file where the default refresh rates, etc, are. But lo and behold cannot manually install the driver (even unaltered!) - just keep getting an error, even following Microshaft's official instructions on how to install drivers manually. This is another common problem when installing Microshaft Windows 7 drivers manually, as I found out online.

What is so frustrating is that official Microsoft documentation explains over riding EDIDs, but it doesn't work. And their support staff are utterly useless when it comes to slightly challenging stuff.

The T42 is fine and fast running Windows 7. The only issue is this screen flicker problem, which is not only a ThinkPad T42 issue; see the amount of complaints ion the web.

[JBUK]

Would hztool help your flickering at all ??