Monitor OK in Safe Mode but black screens even with VGA boot

[grissom]

I have an HTPC that at the moment is connected via HDMI to an old HD ready LCD TV that mostly expects to receive 1360x768 at 60 Hz. It is an Ivy Bridge Pentium G2020 (just iGPU), running Windows 7 Pro.

This has been bothering me a bit, because essentially no video content is in this format. I have also been aware of black crush issues with Intel video, supposedly fixed in a newer driver, so I thought I would update the driver and play around! As I live in the UK, I was wondering if I could get the TV to accept 1280x720 at 50 Hz, which is the typical format of BBC catch-up services.)

I began by updating the driver and then installed Monitor Asset Manager from Entech Taiwan to see what the TV is capable of displaying. This revealed an EIA/CEA-861 extension block in the EDID data with some additional video modes not picked up automatically by Windows.

I generated a custom resolution with the Intel driver utility CustomModeAppV2.0.exe with these values. I had not really expected the resolution would be applied immediately upon its creation, but it was. The TV displayed the text "720p50", and I had a picture, albeit the desktop was overlapping the bezels both horizontally and vertically. I used the Intel driver settings to scale the aspect ratio until there was a better fit to the screen. It was OK - the desktop was a bit blurry, but I was thinking I might try it with some video for a more relevant comparison with 1360x768 at 60 Hz.

Anyway, at some point I rebooted the machine for some reason, and after the Windows "starting" logo, I got a black screen and the TV displayed "Out of range".

I can now boot into Safe Mode, but this does not help me, because the Intel video driver is not loaded (which is why the TV works), so I cannot apply a more standard resolution through the driver. Frustratingly, another boot option to "Enable low resolution video", which theoretically loads the driver with standard (low res) display settings does not work - I get an immediate black screen after the Windows logo. I can remote into the machine, but again Remote Desktop does not allow one to change video settings. From Safe Mode, I uninstalled the Intel video driver, and I could then boot normally with the display working fine (but at 800x600), but when I reinstalled the driver, I got the black screen back again.

What should I do?

I am thinking:
1. I could try installing Teamviewer or Logmein or VNC, to see whether I can access remote video settings with those services.

2. I could hack the registry, to try and delete the offending custom resolution, but I don't know where to look yet, and it seems like there is potential for making things worse.

3. I could find a monitor that can display 720p50 with whatever horrible aspect ratio scaling the iGPU is applying.

4. Various voodoo to do with plugging and unplugging the TV, the HDMI cable, the computer, the CMOS chip.

5. Adding a VGA connection from the PC to the TV - will this give me another set of video defaults? I think I have VGA on both ends, although I haven't even thought about VGA for a while.

Anyone know whether Number 1 will work, and if so what specific software would you recommend? Any other ideas?

I am going to sleep on it (on UK time here), so you have hours and hours to ponder my dilemma.

 

[Iron Woode]

it's probably remembering the custom setting you created.

I wonder if there is a program to completely erase the driver and its settings?

or maybe some way of allowing a clean install.

I found this: http://www.guru3d.com/files-details/display-driver-uninstaller-download.html

what about using system restore?

 

[grissom]

Yes, these are good ideas. The guru3d GPU uninstaller seems to have a focus on AMD and nVidia discrete cards, but the principle of a thorough registry clean-up is a good one.

In fact, I think I have found the offending registry keys, so I will just delete them in my "current control set", knowing that I can revert to the "last known good" control set if I need to. I wish I had thought of that at the beginning!

System restore would likely work, but it has always seemed like a bit of a nuclear option to me, probably through ignorance on my part.

 

[grissom]

Well, my attempted registry hack didn't work. I found I had a recent (but pre-crisis) system restore point, so I did a system restore, but unfortunately that was also ineffective.

I am thinking maybe I could execute a Powershell script on startup that changes the display resolution. What a nightmare!

 

[VirtualLarry]

I would give the VGA cable to TV a shot.

 

[grissom]

I would give the VGA cable to TV a shot.

I just did that, and everything works fine. But if I switch to the HDMI input, I still get a black screen. On the other hand, in Safe Mode, the HDMI connection still works, and during bootup it even starts at 1360x768 as far as the UEFI splash screen.

I think I am going to do a factory reset of the TV once I have noted down my picture settings, but I've just noticed I have a second HDMI connection on the TV, so will try that as well.

 

[grissom]

The second HDMI connection behaves the same way as the first.

Also, the instructions in the manual for reseting the TV do not work. They require use of the TV's remote control, and I appear to have a different remote compared with what was supposed to have been supplied with the TV.

*Expletives in the mind of the poster*

 

[grissom]

Well I think the supplied remote may well be very similar to that officially specified, and I do think it was in fact the original equipment supplied to me. Nevertheless, the reset process isn't working.

Anyway, I'm back to thinking about the Display Driver Uninstaller (as on guru3d.com), although I'm reluctant to lay waste to the registry.

 

[grissom]

****

OK, so I tried the Display Driver Uninstaller 17.02, from Safe Mode, rebooted as a normal user with the basic VGA driver, resinstalled the Intel driver ... and I am back at Square 1.

In fact, I am back with the resolution I was using through the VGA input, which was not the original default, so some part of the graphics and/or monitor setup has obviously carried over despite the registry cleaning.

Maybe I'll just use VGA, although I can't get 1360 x 768 at 60 Hertz on that input, despite the TV manual recommending that as a possible VGA resolution. I am pixel mapped at 1280x768, 60 Hz, with black bars on the sides of the screen.

I suppose more registry hacking is required.

 

[grissom]

Well, I have finally got a very hacky way of recovering my HDMI connection, but it doesn't survive a reboot.

I downloaded DevManView.exe (v. 1.48) from NirSoft. This is like Device Manager, except it allows you to disable and restart drivers on the fly, and also provides detailed information about the drivers, including for example their associated inf files and sections, and some info about their registry parameters.

So I remote in to the system after it has booted up, then disable and re-enable the Intel graphics driver. With both VGA and HDMI connections in place, the driver seems to come back up in a multi-monitor setup with a 720p 59 Hz common resolution, with an extended desktop, each visible when I switch display inputs on the TV remote.

From here, I can make whatever changes I like, e.g. unplug the VGA cable, set a 1360x768 resolution for the HDMI connection, and just use the system as I always used to.

The annoying thing is there still seems to be a bad video driver initialization routine on bootup. I am not sure why that would be the case, because after all when I shut down I am in the normal 1360x768 configuration, so any bad mode line (custom resolution) that I created for 720p50 shouldn't be reloaded.

On the upside, I don't necessarily have to reboot the machine very often, and anyway even the VGA connection seems to decay gracefully from 1360x768 to 1280x768 when I switch inputs.

 

[grissom]

It turns out that I can actually deal with this through Device Manager as well (from an RDP session so I can see what I am doing). There is no need for the VGA connection to the TV to be present either - the Intel driver, when restarted after boot, seems to come up in a saner state. Perhaps I could add a task to Task Scheduler to automate this.

Interestingly, when one disables the graphics driver, the system falls back to VGASAVE, and one gets immediate visibility on the TV, yet the "Enable low resolution" boot option, which I think relies on VGASAVE, still comes up with a black screen.

Also, I notice I have a backup of the registry from a few months ago (in %Windows%\System32\config\regback ), so I plan to open the System hive with an offline registry browser and compare the video related keys. One of the inf files loaded to bring up the Intel graphics adapter must be grabbing some bad configuration data from somewhere, so if I can determine what is different in the registry, perhaps I will be able to determine the source of that discrepancy. I know there are "helper" drivers (miniport and such like) that can be involved, and for whatever reason, once booted, the bad configuration pathway is not revisited. Given this seems to affect VGASAVE as well (because low res boot doesn't work either), it is likely something early in the initialization sequence.