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Hervé

Enabling DVI/DP/HDMI and increasing VRAM with Intel Haswell/4th gen HD4200/4400/4600/etc. iGPU

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Sorry forgot about the kexts. This time I removed WG and FakePCIIntel*. Tried different resolutions of built-in LCD but external display is still blank.

 

I think when I plugin the the cable there IS some signal sent to the monitor, because the monitor wakes up and the built-in screen saver stops. However, immediately after that there is no signal and the monitor goes to sleep again. IOReg has the correct monitor information registered (vendor id, product id, EDID). But SysPref->Display cannot find another monitor.

 

I also tried the sleep function and it still breaks (KP) :(

 

At some point (several days ago) I was able to get the video out on the external display. But while trying to fix the sleep/shutdown KP I tried different things, and now I cannot even go back to that state. I can never get it NOT cause KP when the docking station video cable is plugged in.

 

Although the specs are very similar between a E6440 and E7440, I'm wondering if there is some fundamental differences. I've searched for days but haven't found any E7440 working with docking station (while there might not be many users trying hackingtosh). My concern is if there is some "internal" bug that prevents it from working properly. But the laptop did work 100% with the dock and video when Windows was installed.

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Can't see what could be wrong with the E7440, sorry.

 

I've been playing a little more on the multiple external displays arrangement and modified the Azul FB patch for dual DVI outputs:

Dual-DVI_patch.jpg

 

I can then hook 2 x DVI screens off an E-Port Plus docking station (the wide model with 2 x DVI ports):

3_Displays_HD4600.jpg

 

However, initially, I reproduced the DVI black screen issue I experienced at home when attaching DVI + HDMI displays to my E6440:

IMG_1744.jpg

 

IMG_1746.jpg

 

The screen that went black was the 19" Dell 1908WFP attached to DVI output #1. @1440x900, it's got a lower max. resolution than the 21,5" Full HD Dell P2211H @1920x1080 attached to DVI output #2.

 

So I thought the issue could be related to resolution. After various adjustments, I found that, in order to obtain video output on both external displays, the larger screen must not be set to a resolution higher than the highest of the smaller screen. Otherwise the screen with lowest capacity goes black or displays snow. But I cannot select just any lower res, some remain incompatible with the smaller screen! 🙄

 

I could therefore settle for resolutions both screens had in common such as @1360x768/@1280x960/@1024x768 or set the smaller screen to its max. res. @1440x900 and the larger screen @1360x768:

1st_DVI_screen.jpg  2nd_DVI_screen.jpgIMG_1749.jpg

 

It would also appear that combinations and/or ratios of resolutions applied to the screens may impact video output. For instance, if both screens are set to 1360x768 which is 16:9, I can set the small screen to 1440x900 which is 16:10 and retain full video outputs. I can then set the large screen to 1280x960 which is 4:3 without any impact. If I further reduce the large screen to 1024x768 which is still 4:3, small screen goes black. If I then set the large screen to 1280x1024, I get snow on the small screen. This snow will remain when I return the large screen to resolutions that previously work. If I then set both screens to 1360x768, video output resumes on both screens and I can then set the large one to 1280x1024 without any loss of video! Can make that one out...

 

NB: If I swap DVI outputs and place the large screen on DVI #1 and the small screen on DVI #2, it the large screen that goes black.

 

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Great debug work, Herve! This can definitely be one thing to try.

 

One question: it's nice that your monitor actually tells you what the problem is! Mine just says "no signal". When the resolution was not correct and the monitor was blank, were you able to find the monitor in SysPref->Display? My problem is that I cannot see this monitor there and I don't know how I can change the resolution (the monitor does show up in IOReg). But you are absolutely correct, my monitors also have different resolutions.

 

Another thing is that I can never get that display panel work correctly since I installed 10.13.6. It never shows the monitor info even if I use built-in HDMI and video works perfectly. All I get is this:

 

image.png.21466dc9b6a6a662106bd3424787a11a.png

 

No monitor or other options can be found.

 

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Yes, I can see all 3 x displays in the Displays PrefPane at all times; both external displays are properly detected, there's only a resolution issue / conflict / incompatibility. That's shown in my 2nd illustration above.

 

No display preference tool in OS X/macOS Finder's bar since ML. Look here for alternatives.

 

DisplayMenu.jpg

 

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