Second monitor not detected: T430s with Mini Dock Plus Series 3 dual external monitor

[keeena]

I'm using a T430s and a mini dock plus series 3. This is the dock with the dual DVI, dual DisplayPort, 1x VGA. I do not use the laptop's built-in screen; just the 2 external monitors. Intel HD4000 graphic chip and Nvidia Optimus/

I previously had 2 20" monitors with a 1680x1050 resolution using DVI-to-DVI. They both worked fine.

I upgraded to 2 24" monitors with a 1920x1200 resolution. The laptop is not recognizing the second monitor.

I have tried:

• dual display port (dock side) to mini display port (monitor side): only 1 monitor recognized
• dual dvi (dock side) to HDMI (monitor side): only 1 monitor recognized

I ruled out monitor and cable problems by swapping...each by itself works fine. Looking up specs, I believe this resolution should be supported by DP or DVI. Can anybody confirm that this is a supported config? Any ideas what is wrong?

UPDATE - I did try 1 DP/mDP and 1 DVI/HDMI: this does work. However, its not an ideal solution because it would interfere with the monitors ports which I want to use for a second PC.

UPDATE 2 - OK, now I am beyond aggrivated. I also have a support ticket w/ Lenovo where they suggested switching to Integrated Graphics only in the BIOS. I tried that, no luck. After changing that setting back, i tried to get my 1 DP / 1 DVI working, but now it would not recognize dual monitors. ???

After some testing, I'm finding that the -only- setup that works is the following:

Dock DVI port 1 to Monitor A

Dock DP port 2 to Monitor B

If I try this (just plug swap DVI and DP to other ports on the dock)

Dock DVI port 2 to Monitor A

Dock DP port 1 to Monitor B

Fail - Monitor A will is not recognized and Monitor B connects with 640x480 resolution and no apparent way to change it. Monitor B is just identified as Generic Non-PnP Monitor.

What is going on?

UPDATE 3 - I'll just talk to myself while folks are having Thankgiving turkey.  Just more data dump:

I tried many combinations of Monitor / Cable Types / Dock Port1-2 and the only thing that works is the one I listed above. I hit a case where I thought one DVI cable may be bad, but works perfectly fine in a different PC. I got my hands on regular DP/DP cables (not DP/mDP) - same problems. Also tired a 2nd dock; exhibited all the same problems.

When the machine boots, the initial windows logo will appear on 1 monitor, then flip to the other monitor. So it seems to confirm that connectivity-wise: both monitors on DVI (or DP) are recognized. However, its only 1 at a time.

One obvious thing I've nailed down is that the DisplayPort dock port "#1" seems to be constantly stuck: it will not recognize the display, even if its the -only- display connected. It will always state a Generic Non-PnP w/ a 640 resolution.

And yes - I read through the couple of longer threads here on the T430s. Those threads deal w/ 3 monitors - this isn't what i'm trying to do. Ultimately I just need this question answered: will the T430s drive 2 external displays via 2x DVI->HDMI or 2x DP (laptop closed...native LCD is off)?

[keeena · Accepted solution]

Fixed; was a driver issue. Problem seems exclusive to a Dell u2415 on DP port 1 only of the dock or to the laptop's DP port (at least for the couple monitors I tried). It's possible it could affect other monitors.

My starting point: 9.18.13.4535 / 9.17.10.2843 (Nvidia /  Intel)

The latest driver from Lenovo is 9.18.13.4535 / 8.15.10.2725. I'm not sure how i have a slightly newer Intel, but that's what it was.

I couldn't install the Lenovo driver. I also couldn't install a newer driver from Intel (10.18.10.4276). In both cases Windows or the Intel installer stopped me saying the mfr provided the drivers and that the installed version was up to date.

I worked around by first rolling back the Intel driver. The manual (.zip) install of the latest intel driver worked. This immediately fixed the Dell u2415 on DP port 1 and laptop's built-in DP port.

[keeena]

Well, not quite fixed. Setting doesn't persist after a reboot and/or undock (?).

[4229tech]

I would like to know if you found a solution.  I am trying to run two monitors one from a VGA port the other from DVI-D port.

This is not fun trying to run down solutions....

[mattcoll9]

I can confirm that this works - as i've been running it for some time. (until recently) - that is "T430s Mini Dock Plus Series 3 dual external monitor"

I only have intel Graphics 4000 though so that could be a difference

One trick was that the "new monitors" i purchase (Benq) were not set to use the ports as needed.

Once i set the monitors to the correct ports (autodetect or HDMI) then it works fine.

Mine has now however (as of some recent update) stopped detecting that it's redocked, and won't switch back to the correct monitor settings- and requires a reboot every time i redock.

See here:

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T430S-on-thinkpad-mini-dock-plus-series-...