Monitor goes missing after driver update

[QQBoss]

I am hoping I am missing something silly, but my 2560x1440 monitor isn't working after an AMD Catalyst update, and rolling back isn't helping.

I have 3 monitors: 1440x900 Dell, 2560x1440 HKC T7000 (Chinese brand, used as my primary), and a 1920x1080 Sharp TV. I am running fully up-to-date Windows 8 with no overclocking (beyond factory) of the video or CPU. My video card is a HIS ICEQ 7870 with the Dell plugged into the DVI port, HKC into the HDMI, and the Sharp plugged into on-board Intel HDMI port.

I was running Catalyst 13.4 and everything was working fine, but on a lark I decided to update to the beta 13.8. Upon installing the graphics driver, my HKC monitor displayed 'no video'. Rebooting has the monitor working, up until just before the Windows 8 lock screen, where it will cut out and the Sharp becomes the primary at that point. Moving the HKC over to the onboard HDMI gets it working again, but at only 1080p, seems the i5-2500K can't drive it to 2560x1440, oh well.

I deleted the driver, and all three monitors worked again at their default resolutions in their respective ports. I reinstalled 13.4 and the HKC disappears again, even not showing up in Device Manager. This seemed obviously related to the HDMI port getting disabled or something by Catalyst, until I plugged the Sharp into the 7870 HDMI port and it works fine (while the T7000 is in the on-board)!

I am sure I must be missing something simple, but since I can't even see the HKC in device manager when it is plugged in to the 7870 (but I can see the Sharp), I am not sure where to begin. Any suggestions will be greatly appreciated, because I finally decided to see whether this HKC will handle any overclocking beyond 60Hz.

 

[Black Octagon]

Use the DVI port for the HKC

 

[QQBoss]

While I will grant you that this isn't a completely unfeasible option, I wonder why it should be necessary when I was using 13.4 and everything worked fine, but after uninstalling and reinstalling it doesn't. That will likely be my hack workaround if I can't find what switch or setting I am missing to get it working just like it was working before, though.

 

[Black Octagon]

Because via HDMI, 2560x1440 shouldn't be possible over to begin with (unless you're forcing it as a custom resolution with a refresh rate below 60Hz). 2560x1440 at 60Hz typically needs DisplayPort or Dual Link DVI. If it was working over HDMI before your driver update then I'm impressed and confused, because it shouldn't have been.

 

[mikeymikec]

I think you might be wrong about its maximum resolution:

http://en.wikipedia.org/wiki/HDMI#Versions

 

[Black Octagon]

^Ok fair point but my understanding is that only 4k displays are starting to use sufficiently-recent iterations of HDMI to support anything above 1920x1080.

Here's a Chinese review of this monitor: http://lcd.it168.com/a2012/0807/1381/000001381938_all.shtml

Using Google Translate, the final section says the following:

Jingdong REVIEWS
　　Here, the author has been specially excerpt Jingdong buy this monitor users reviews, which for this display screen effects and cost performance is more recognized, some disadvantages are also concentrated in the details of the work area should be improved. In addition, many users react to connect this monitor can not output using HDMI interface 2560 × 1440 resolution, can only reach 1920 × 1080 Full HD standard, it should be said that this is a common phenomenon in this monitor, I also encountered the same when measured problem, it is recommended to buy this monitor users try to use the DVI cable to use gift.

 

[QQBoss]

Another good idea, but I wasn't forcing any custom resolutions. This HKC panel fully supports the HDMI 1.4 standard, as well as displayport 1.2, so 2560x1440@60Hz isn't a problem (and probably higher). I have been using it over 6 months in this configuration, and didn't have any problems going from 13.3 to 13.4, for example. If I have to switch to another cable, I will probably try using a displayport cable rather than switching to DVI because my old Dell monitor can only accept DVI so I won't have to switch anything around.

And even if you were right, it wouldn't explain why the HKC doesn't appear in device manager when plugged into the 7870 HDMI port, but the Sharp does, since the HKC has no problem dropping back automagically to 1080p if that is all it is supplied.

Your point about 4K is well made, though. I am not doing any further motherboard/video/monitor updates until I can get 4K@60Hz over a single HDMI and NGFF SSD storage on the mobo. Maybe by then, for my work where I can benefit from it, I can get a 27 or 30" 4K panel at a reasonable price from one of my Chinese vendors- this T7000 only cost me US$300 for pixel perfect and multi-input, with reasonable bleed and color accuracy (though it isn't a 10 bit panel, which I wouldn't complain about). It isn't available outside of China as far as I am aware, though.

edit for addendum:
I probably should reiterate that when the AMD display driver is removed from my system, the HKC panel is driven just fine by the 7870 at 2560x1440@60Hz over the same HDMI port that doesn't work (only with the HKC) when the driver is being used. However, I strangely lose the ability to drive my Sharp at 60Hz, even though it is being driven by the on-board video, not the AMD card, and the Intel control panel says it can drive the panel at 60Hz.

I think the time has come for me to escalate this to HIS support and see what ideas they have.

 

[QQBoss]

Seems no advice anyone had for me resolved the problem, but buying a Displayport cable and using that with beta 13.8 of the Catalyst Control Center did fix the problem. As an added bonus, I was able to overclock my monitor to 75 Hz. Hopefully that will ease some of the eyestrain I have had.

Still no idea why the HDMI cable stopped working, though. The current set up working is enough for me.

 

[tential]

Anyone else think his monitor ran away from a driver update?

I got a little worried. "Not updating drivers for fear of monitor running away!"