Latitude E7450, E-port 2, U2715H - dual monitors - unstable configuration

No responses, so I will add my own, on the way towards a solution, which I believe requires driver enhancements. Are you listening, Dell?

Together with a colleague who knows better than me what to look for, we discovered:
- The Intel HD graphics control panel -> Display port topology only discovers one, not two display ports. This could be a problem with the panel or with the graphics driver.
- Both Intel and Nvidia have more recent driver releases for their respective hardware components in the Latitude E7450 than those available from Dell but they cannot be installed directly. (NVidia 353.06 vs 341.27; Intel 10.18.10.4222 vs 10.18.14.4099 - I suspect digits 5 and 6 reflect an OEM numbering scheme). Intel says their driver update includes critical fixes for display support.
- When we attempted to install the latest Nvidia driver, the display flashed in what seemed to be a non-trivial manner (before the update was automatically aborted). This could be related to a conflict between the two drivers.

I also discovered that even when only one of the Dell U2715H monitors is connected, it frequently goes black when it shouldn't. So it is not a question of a dual monitor configuration as I originally thought. I have also swapped docking stations to eliminate random hardware error in this component. The Intel driver's handling of display port(s) seems to be the most likely culprit.

Guessing from seeing repeated patterns of monitor behavior, a more precise diagnosis could be that the monitors do not always go out of power save mode when they ought to. I suppose that for a workaround I could experiment with power settings to make sure they never went into power save mode (so they wouldn't have to be brought out of it again) but I haven't done so.

We have, however, found a workaround that gives a much more stable configuration: to daisy-chain the two monitors from one display port. Even in this configuration the second monitor has gone black on occasion but for now this is an acceptable workaround. However, the Windows Main Display needs to be the first in the chain, or else it will not work properly.

Received some feedback from a customer with this issue, a newer intel video driver improved but didn't fix the issue

I have the same problem! But with two U2515H displays, Lattitude E7450, Euro 2 docking. Using displayport.

Are you looking in to this Dell?? 

Hoped that windows 10 would help me, but it dont look like it will help. I will try to chain the monitors as you did.

I had no problems with Win 7 and resolution at 1920x1080. But i want the higher as this was the reason why we did buy these monitors! All products is Dell. So come on Dell. Please check out dis issue!

Best Regards

Update: I have now installed new drivers: Intel 10.18.14.4170 (dated 16 March, 2015) and Nvidia 10.18.13.5362 (dated 22 July, 2015). I found them both by browsing Dell's support section for the 7450. Neither Windows nor Dell software was able to discover these automatically, and the wrappers have a more recent date (they contain other drivers as well). I cannot explain why these version numbers do not match those I referred to previously. My configuration as described (with the daisy-chain setup) has now become much more stable. Over the last week and with these more recent drivers I have hardly experienced any screen blackouts, except occasionally when booting or rebooting the computer. A new reboot usually solves that problem. So the situation has improved with the new drivers but it is far from as stable as it should.

Had 1 laptop with this issue; Dell replaced the mainboard last week

What did you do to make them replace the motherboard (e.g. any particular diagnostics)? And - more significantly - did it help?

Here at Penn State University, I have had many colleagues voice the same issue with erratic monitor behavior.  Things seem to be more stable with the latest BIOS update (A05) and Intel video drivers.  

Haven't been able to test this firmware, sounds like a possible fix?

---- 

http://www.dell.com/support/home/us/en/04/Drivers/DriversDetails?driverId=29D8V&fileId=3482013792&osCode=W764&productCode=latitude-e7450-ultrabook&languageCode=EN&categoryId=VI

Synaptics VMM3320 MST HUB Firmware Update

This package provides Synaptics VMM3320 MST HUB Firmware Update and is supported on Latitude E7250/E7450 that are running the following Windows Operating System: Windows 7, Windows 8 and Windows 8.1

Fixes & Enhancements

Fixes
- resolves momentary screen flash when using external DVI/VGA display

Unfortunately, this firmware update did not solve the problem in my case. Or to be more precise: A few days ago, I started the Dell Command Update utility and it updated a number of applications and drivers plus the laptop's BIOS to version A05. (Even though the A06 had been released a couple of days earlier, the utility only picked the previous version.) This did not solve the problem, but it remained manageable. I then installed the Synaptics update suggested by Turnhout, which appeared not to have been discovered by the utility either. After the Synaptics upgrade, both monitors seemed to be working flawlessly, for several days, until I installed two Windows updates (as per company policy) today. Then the second monitor started dropping out again. So I don't really know if the Synaptics solution would have lasted if the Windows update had not taken place.

I dock my laptop and run the DVI cable to one monitor and VGA to the other.  This has always worked great for past laptops but this new one has an annoying problem...  Any monitor connected to the dock's VGA adapter will have a subtle but very annoying "jitter" to it.  For example, when you look closely at words you type, or the outer edge of a window, it is not crisp and stable.  It seems to be moving.  It makes me think the laptop is a step down from the E6430 that I had instead of a step up.  I feel like we have a junk video card in this laptop.

So my testing has narrowed the problem to the VGA port when docked (dock is not the issue because it happens both at work and at home, using different docks).  If I bypass the dock's VGA port and connect VGA cable to the laptop directly (via the included DisplayPort adapter), the screen works perfectly.  But of course this sort of defeats the purpose of using a dock because it requires messing with connections.

My next thought is to contact Dell Support and see what they say about this.  To me this is a defect that needs to be corrected.

Yet another update on my specific configuration. After one or more new updates of drivers and bios (I have lost count), new symptoms have appeared. On each monitor, the rightmost one-third of the area consists of three overlaid images: the image that should be there, a copy of the leftmost one-third, and a flickering pattern of tiny triangles. I have reported this to Dell Pro Support. They have confirmed that they have managed to reproduce the problem but they do not have a set timeline for solving it. I suspect this involves a root problem, possibly concerning timing, that may also be involved in similar problems with other configurations reported in this thread.

I fortunately have found a workaround: to lower the resolution and then set it back to full resolution again. It works, but it is a bit annoying to have to do this almost every time I boot the PC in its docking station.

I am having this same problem but with E7250.  I have 3 users with the same laptop but 3 sets of different monitors.  They are either connected by DVI or DP cables.  All users are on the latest BIOS A08.  I have used the Windows, Intel, and Dell Command Update software and have installed all driver / software updates.  Nothing is working.

The symptoms are one or both monitors will flash and or flicker and occasionally one of the monitors will just go into power save.  I have to reboot the computer to get the monitor back on.

UPDATE - 11/3/15 - I was originally using 2 DP cables, then I tried 2 DVI cables.  I then switched to 1 DVI and 1 VGA cable.  So far, for the past day, the user has been ok.  Keeping my fingers crossed. 

At my work we have a number of these E7450 laptops with similar issues.

So you guys are not the only ones.

Some laptops/issues have been fixed/helped by motherboard replacements but others haven't.

We have an active case with support and they are still working on it.