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timcirrus
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Posts: 5
Registered: ‎01-13-2015
Views: 14,175
Message 1 of 13

T440s Mini Displayport Issue

Hello All

 

Really frustrating issue here that I can only find hints about around these forums and the net.

 

New T440s for work - bought 6 weeks ago. Very fresh. PreInstalled with Window 8.1 which was then seemlessly upgraded to 8.1 Pro. PC has then been kept up to date with Lenovo and Windows updates.

 

Am trying to run the following monitor setup at work - I do NOT have a dock:

  • Main Display - Samsung 205BW - connected to VGA port
  • 2nd Display - Samsung 205BW - connected to MiniDisplayPort
  • 3rd Display - Laptop LCD

 

Eyes are getting old so I plan to use the two monitors mainly - with the LCD as backup real estate.

 

The monitor on the laptop's VGA port is working perfectly - max resolution, max refresh rate, everything.

 

The problem is I cannot get the 2nd display to work in DVI from the miniDP port in any resolution. Windows appears to detect that something is there but the monitor itself does not detect any digital signal and it remains black. I got a miniDisplayPort > DVI adaptor from the local pc shop and tried both single and dual link DVI cables but nothing worked.

 

I CAN make the display work if I use a minDisplayPort > VGA adaptor and set the res to the max 1680 x 1050 but I get a weird effect where the monitor will filcker and go black, then come back, and go blank again, repeatedly until the monitor loses the signal altogether. I can reduce the effect if I lower the resolution to 1440x900 but it can still happen, mainly when there is certain level of "activity" on the screen like a video and I'm moving windows around, or I have 3 or 4 windows open onscreen. The more wierder-er thing is if I still have the offending window grabbed by the mouse, and I move it back OFF the monitor, it comes back to life - If I move the window back onto the monitor the black flickering effect occurs again.

 

From what I read about DisplayPorts, there is no reason why I shouldn't be able to get the max res of 1680 x 1050 which the other monitor gets from the laptop's VGA port, and Windows recommends. If I set that resolution, the monitor goes black again - changing the refresh rate does nothing. In fact, there is no reason why I shouldn't be able to use the miniDP > DVI adaptor either. I'm not editing video or gaming and I dont want microscopic fonts on screen.

 

Intel drivers are the latest from lenovo's site - there appears to be more up-to-date drivers on the Intel site but the PC says I'm not "allowed" to install those Smiley Wink Pretty sure this isn't an issue with the monitors - they are old but I've tried 3 of them now and I get the same effect on all three on the minDP port only.

 

As a side issue - the Windows Resolution app is really messed up with identifying the displays - it keeps getting the external monitors mixed up with its numbering and setting the main display works properly only sometimes.

 

Help please anyone!

 

 

Guru
Posts: 9,598
Registered: ‎12-26-2009
Location: CA
Views: 14,158
Message 2 of 13

Re: T440s Mini Displayport Issue

You can force the Intel drivers to install using Have Disk in Device Manager.

Do you also happen to have the GT 730M in your T440s?

W520: 2960XM, Q2000M @ 1091/1380, 32GB RAM, 500GB&750GB HDD & 500GB SSD, FHD&MB168B+
X61T: L7500, 4GB RAM, 500GB HDD, XGA screen, Ultrabase
W550s: 5600U, K620M at 1164/1281, 16GB RAM, 512GB SSD, 3K touchscreen
X200s: SL9400, 6GB RAM, 64GB SD card, WXGA+ screen
TPT1: 1839-23U
timcirrus
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Posts: 5
Registered: ‎01-13-2015
Views: 14,151
Message 3 of 13

Re: T440s Mini Displayport Issue

Thanks Colonel

 

I got the latest direct-from-intel drivers installed so now I'm at version 10.18.10.3907 where the offical drivers from Lenovo are 10.18.10.3383.

 

I've got the second monitor now at 1600 x 900 @ 60kHz, which is only 1 resolution setting away from the max of 1680 x 1050. The flickering on the right of the monitor is still there but very infrequent but the complete black "flashing"/signal loss type behaviour is very infrequent as well...for now. It still on miniDP > VGA - the monitor still refuses to fire up when using the DVI adaptor (and duallink cable). I'm going to start using it to see if it is indeed useable. I'd still like the max res and to use DVI if I can.

 

The weird thing with the DVI adaptor is that Windows thinks something is there, allows me to change the res, etc and the mouse behaves as if it is moving onto the third screen, but the monitor itself refused to auto-detect the digital signal. I'm now suspecting the cable but I dont have another dual link cable handy. Or may be the monitors are too old to cope with Displayport signals *shrug*

 

I'm in Australia and I don't believe any of the T440s are offered with the NVidia cards in them - at least mine doesn't have it.

 

Lenovo Support Partner
Posts: 451
Registered: ‎07-16-2013
Location: SI
Views: 14,126
Message 4 of 13

Re: T440s Mini Displayport Issue

Did you try some other brand od mDP-DVI adapter? Or use converter cable instead adapter? Did you update firmware on T440s?

***

Disclaimer: I am not Lenovo employee. While I do work for Lenovo Partner, all my contributions are my personal, non-official and not that of Lenovo or my employer.


timcirrus
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Posts: 5
Registered: ‎01-13-2015
Views: 14,107
Message 5 of 13

Re: T440s Mini Displayport Issue

Yup - firmware is the latest from according to the lenovo update utility.

 

No - I haven't tried another adaptor or convertor cable yet. At $30+ a pop for the adaptors and as much again for the cables, this is getting to be an expensive and frustrating exercise, even if it is just for work. There's a computer market this weekend where I might be able to get these things cheaper. I could order something online but if it still doesn't work, I'm left with a unless adaptor and money up in smoke.

 

<rant>

How hard should this be?? I'm certainly not pushing the upper limits of the spec'd resolutions from this port and I'm running on VGA so it should be a snap for the port to handle. After the last update of the intel drivers (from intel not lenovo), the screen on the miniDP port appears more stable, but its still unstable enough to be annoying for work purposes - maybe Intel aren't putting their best into updating this driver *sigh*

</rant>

 

Anyway, will have a look around for a converter cable to try and take the adaptor link out of the equation Smiley Happy Might even look at ordering the miniDP > DVI convertor that lenovo advertise. I'd have to expect that to work Smiley Happy

ianw01
Token Ring
Posts: 97
Registered: ‎02-08-2011
Location: CA
Views: 14,085
Message 6 of 13

Re: T440s Mini Displayport Issue

I have a few suggestions/questions:

  • Is 3 monitors explicitly supported? I do recall on some older laptops that two external displays was not supported, perhaps due to insufficient video RAM.
  • How much video RAM is allocated in BIOS? Crank it up!
  • Does each external monitor work properly when the other is disconnected? With only one external monitor connected, try external only as well as external + buil-in. Try extended desktop and mirroring. 

Good luck!

Lenovo Support Partner
Posts: 451
Registered: ‎07-16-2013
Location: SI
Views: 14,065
Message 7 of 13

Re: T440s Mini Displayport Issue

T440s does support 3 displays (for example see here and here).

So it has to do with your monitors I believe ...

You don't alocate video memory manually with never chipsets anymore ...

 

Did you try other model of monitor with mDP port? I believe monitor may be non-compatible to your NB ...

***

Disclaimer: I am not Lenovo employee. While I do work for Lenovo Partner, all my contributions are my personal, non-official and not that of Lenovo or my employer.


timcirrus
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Posts: 5
Registered: ‎01-13-2015
Views: 14,039
Message 8 of 13

Re: T440s Mini Displayport Issue

Hi All

 

Thanks for all your replys.

 

I've tried just one external monitor in the miniDP port - disconnected the VGA port - no change. Monitor still refused to fire up on DVI mode and can't get native/full res on VGA mode (can only go up to 1600x900).

 

Also tried another Samsung 205BW monitor - same behaviour. I don't have another brand of monitor in the office to try.

 

I noted from the link that Toruk posted that the spec states "3840x2160@30Hz (DisplayPort via Mini DisplayPort cable on integrated models);" - the @30Hz intrigues me. I'm going from miniDP > DVI but since I've got a LCD, refresh rate shouldn't matter right? On the offchance, I've tried to set a custom resolution via the Intel utilities to 1680x1050 @ 30Hz and while the utilitiy appeared to create it, it didnt seem to apply it and Windows didn't pick it up as a resolution or refresh rate I could set.

 

I've found hints to changing Vsync from + to - and things like that but I'm fast getting out of my depth.

 

I've got a video of the effect I'm seeing on the 2nd monitor if anyone is willing to have a look - you'll see the flickering of the image on the right of the screen, and you'll see the screen going blank and coming back. Sometimes the blanking will be permanent, and I have to unplug the screen from the minidisplayport, let windows reorganise the screens, I'll move the windows to another monitor and then plug back in. This is all with the miniDP > VGA adapter and the res set to 1680x1050. If I set the res to 1600x900, then the monitor is a lot more stable as long as I dont "overload" it with too many windows and/or screen movement - sometimes just moving the mouse over it is enough to make it unstable.

 

If I use the mDP > DVI, I get a blank screen regardless of the resolution, but Windows behaves as if there is something there.

 

Video Link

 

 

 

 

 

dizzbuster
Punch Card
Posts: 65
Registered: ‎03-06-2014
Location: US
Views: 14,016
Message 9 of 13

Re: T440s Mini Displayport Issue

As much as i hate to say it i think you have a buggered display port connector on yout t440s. You mentioned the flicker which tells me you have a bad physical connnection. I run into similar issues with a Dell work laptop that uses a mini hdmi connection for external monitors - i need to make sure the cable is firmly seated. I have a t440s as well and have no issues with the mini-dp connector driving monitors.

ianw01
Token Ring
Posts: 97
Registered: ‎02-08-2011
Location: CA
Views: 13,988
Message 10 of 13

Re: T440s Mini Displayport Issue

Toruk, on my i7 T440s with Intel graphics, the BIOS offers either 256MB or 512MB "Total Graphics Memory" under Config > Display. I think that 256 is the default.

 

That said, I also tend to suspect physical connection issues where plausible, so my money is on dizzbuster's DisplayPort connector hypothesis.

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