switchable graphics and external monitor through port replic

[lponz7]

I have a T400 with Vista HP. Recently, I updated to the new version of switchable graphics that became available on System Update. Since then, when I boot up after docking with an external LCD (lid closed since I use the monitor stand) I receive a BSOD. The only way to avoid this is to switch from discrete to integrated graphics before I dock.

Before updating, what would happen is that I would automatically be switched to integrated graphics when I docked (assuming I had been using discrete graphics on the laptop), and then switched back when I booted up undocked. When docked, I could not switch to "high performance," but it least it booted without my having to manually make the switch.

As it is, I can't use DVI with the external monitor because there is no such option in the BIOS, as there was for the T61. Now, on top of that, I can't dock without a BSOD unless I manually switch graphics before docking, which is a pain. By the way, my T61 only had discrete graphics and worked fine with the dock and external monitor.

Anyone know what's going on here or have a recommendation for working around this hassle until there's (hopefully) a BIOS update to deal with these issues.

Many thanks. lponz7

[truk]

Since nobody has seemed to express a similar problem, I don't think it's a general problem with the bios. Try re-flashing your bios and re-installing your video card drivers. Make sure that you can boot with the monitor plugged into the laptop, and try to dock with the monitor disconnected. That will determine if it's a problem with being docked, using a monitor, or just both. If you know somebody with a spare dock, you might want to try that.

[georgema]

Someone else on the forum has reported issues with connecting an external monitor while docked. I can't remember the details but it wasn't that long ago so a quick search or trawl through the postings should find it.

You should also check in the W500/W700 forum as well.

Cheers, George

In fact here's the link to the post: -

http://forum.thinkpads.com/viewtopic.php?t=66949

[tixop]

I had the same problem and found a solution [I think somewhere here but can't find the post] that is slightly better than the VGA option.

If you select the discrete graphics in BIOS you will have the option to boot @ DVI. Pay attention that you also need to switch off in BIOS an option saying something like "Automatically detect if OS can use switchable graphics" [working off the T400 right now - can't check the exact description] as it will switch back after each reboot.

Using this option for about a month now without problems. The only downside is that you loose the switching capability - but my T400 is docked 95% of the time so I have no problems with that.

Also, not sure if it makes any difference, but I'm using Vista x64 .

Really hope Lenovo will sort the mess in a future BIOS upgrade...

[AceyMan]

Microsoft just posted a fix for BSoD when you enable/disable external monitor.

http://support.microsoft.com/kb/959252

Apparently this is a side-effect of a kernel update as provided in KB 954211. I had an Thinkpad x61 Tablet user with this issue. We just installed the hotfix and after a quick test looks like this a good fix. (Her unit would BSoD when she undocked from her x6 ultrabase, as well).