I used to mine on NiceHash with both of my monitors working like a charm. But, after today's downtime due to the hack took too long for my liking I switched to Mining Pool Hub, and downloaded the claymore monero miner. I set up everything, and it worked fine, so I decided to start tweaking things.
That's where the problem began. I overclocked my video card with 25MHz, using the config file of the miner itself, on both core and memory clocks, to see whether that worked. Well, first my primary monitor went mono-colour white, and my secondary monitor mono-colour baby blue.
I restarted the PC and on start-up both of my screens featured a BIOS-screen, so everything was connected and working. However, after login Windows did not recognise the second monitor, which was kept dark. I tried using "Display Settings" -> "detect". The device manager did show my second screen though.
So I deleted the video driver, restarted again and suddenly I had a picture on my second screen, it was a duplicate of the first one, but at least crystal clear and working. To my surprise though, Windows still didn't see the second monitor, although the device manager listed it. So I reinstalled my video driver, and my second monitor went dark again, no image, no detection by Windows.
Even a clean install of the driver didn't work: the installer fully removed the current driver, restarted my PC, showing the duplicated screen again, then installed the driver anew and poof, gone was the screen again.
How can I get my second monitor running again? I'm up against it now, and the only thing I can still think of which might help would be a full Windows reinstall, as the monitor seems to be fine.
PS: on my Ubuntu 16.04 LTS build my dual-monitor works like it should, with extended display.
Radeon ReLive 17.1.4
Radeon RX 470