Display port + DVI display issues

[strumpusplunket]

I'm scratching my head over this one. Quite frustrated and can't find anything through Google that exactly matches my situation.

I got an AOC G2460PG a couple of weeks ago, and have been running that as my primary display (via DP) and my old 60Hz Hyundai W220D as my secondary (via DVI), using extended desktop.

It was all okay until a few days ago when I noticed some issues with image on the AOC when the Hyundai was enabled as secondary (but not when it wasn't). Colours were out of whack on the primary. I mean completely out of whack. But the problem went away and came back reliably as I enabled and disabled the secondary display.

Ok, so that was odd, but not too bad since I only use the Hyundai as secondary situationally anyway, when I need some more space for Word docs, spreadsheets, and the like, so I just left it connected but disabled in Windows until I needed it.

But then yesterday it got worse. Suddenly, the PC wouldn't wake from sleep. Both monitors just flickered on a black screen, and the power lights flashed on and off. I had to press the reset button, but then it did a kind of half-reset/half-wake. It POSTed, and then when Windows loaded it came back to the previous state (all windows open as I left them). And then a little later on I started getting chkdsk running every time I restarted. And my keyboard wasn't active so I couldn't skip it either.

I'd noticed already that the BIOS would only display on the Hyundai when I restarted, but it had been okay before. Then it started acting up and running chkdsk every time I either slept/reset the PC or started from cold boot.

I got some errors in Windows relating to the file master table being corrupt. Steam lost my auto login, and some other oddities. I went through multiple restarts repairing with chkdsk, and then it just happened again...

With the Hyundai unplugged it's all okay now, boots properly, the BIOS screen shows on the AOC, no more errors. I'm not 100% sure, but I think the IQ has degraded slightly on the AOC, though. There seems a bit more banding and overly light bias to the shades.

So, why can't I have my secondary display connected? What the hell is going on here?

 

[ExRayTed]

Stop asking questions and RMA the unit. It isn't right - get it replaced

 

[strumpusplunket]

What? It's working perfectly without the secondary display attached. In fact, after a bit more tinkering before I set off for work this morning, I'm even more pleased with the image quality than ever. Really looks nice now. Probably the best looking IQ I've ever had (okay, so I've never had a quality IPS, but still). ULMB and g-sync work fine too. It's only when plugging another display into the gfx card that issues arise.

I'm a bit sceptical it can be a monitor issue if it works without a second display plugged in. And the problems with the display quality on the AOC I noted also appear on the second display if I set it to duplicate rather than extend the desktop, so these issue too are not specific to this screen.

And how could a monitor fault cause boot issues and chkdsk/file corruption problems?

I would have thought it's a graphics card issue perhaps, or either gfx or motherboard BIOS issue?

I don't even know how to go about solving this, or even diagnosing it, but I'd be amazed if it was a monitor fault given the nature and context of the symptoms.