Monitor is only detectable when it's not plugged in

Jedoc

So here's a weird one: for the past few years, I've had a desk with room for only one monitor. I finally got rid of my printer and dragged my second monitor out of the closet, and now I can't get it to connect. I'm running Windows 10 and an AMD Radeon 6800 video card with updated drivers. The monitor is an Envision G218a1.

So far, I've tried:

• Attaching the monitor to the second DVI port on the video card while the primary monitor is plugged in.
• Clicking "detect monitor" in the Display control panel.
• Rebooting.
• Turning the computer off, unplugging the DVI cable from my primary monitor, plugging that cable into the second monitor, then turning the computer back on.
• Unplugging the second monitor, waiting for 30 seconds, and then plugging it back in.
• Pushing all of the buttons on the front of the monitor to get some kind of menu to come up. Only the power button seems to do anything.
• Cursing god.

Early on in this process, I did get a split-second flicker of my wallpaper on the second monitor during a reboot, but since then it's either a black screen or a constant cycle of solid-color screens that goes Grey-Red-Blue-Green-Black and then repeats endlessly.

The thing that really baffles me is that when I unplug the power cable but leave the DVI cable plugged in, my computer appears to recognize the damn thing. I can run my mouse cursor into the dead monitor and it takes a few seconds to run it back, I can drag windows over to the dead monitor and lose them, and my device manager shows that a monitor with the proper model number is connected. But every time I plug the power in, my computer immediately acts like I disconnected the second monitor. It vanishes from the device manager and the Display control panel, and my mouse won't go off the edge of the screen in the direction of the dual monitor any more.

Thoughts? I'd love a fix, but I'm willing to buy a new monitor if you guys think the problem is with the monitor and not my video card.

Foomy

Try using just the second monitor to see if it's the panel itself that's broken or if it's some gpu/driver thing trying to run them both.

Jedoc

Foomy wrote: »

Try using just the second monitor to see if it's the panel itself that's broken or if it's some gpu/driver thing trying to run them both.

Did that! Used same cable and port as the primary monitor and everything. Same deal.

Foomy

If by same deal you mean that it's doing the same things when you hooked up as a secondary, then I'd say you have a busted monitor.

Jedoc

Neat, then. To the monitor store!

spool32

Monitor has an electrical failure - capacitors are charged enough after you plugged it in that it can detect, but it's fucked. If you left it unplugged for a week then tried it, your PC would probably not detect anymore as you've described.

Long and short - replace monitor.

Jedoc

That's really interesting. I know that monitors have capacitors that'll knock you on your ass if you mess with them wrong, but I never considered that they might have enough juice to talk to my computer when the cable's unplugged. Thanks!

spool32

They totally should not be able to do that but some bad shit has likely gone down in the guts of your display.

Shadowfire

Jedoc wrote: »

That's really interesting. I know that monitors have capacitors that'll knock you on your ass if you mess with them wrong, but I never considered that they might have enough juice to talk to my computer when the cable's unplugged. Thanks!

CRTs have that sort of charge, and can hold it for years sometimes. But LCD panels won't hold more than a tickle.

deathnote666

If you suspect monitor issues, try to use the buttons to bring up a menu on the monitor itself. Should come up even when not connected to a computer. If no menus, probably a broken monitor.

I've come across at least 4 failed flat panel monitors over time.

Burtletoy

I had a HD 6850 and it has three ports on the back, 1 HDMI, and 2 DVI.

To run 2 monitors using HDMI and DVI, you have to use the correct DVI port. One will work, the other doesn't do anything.

baudattitude

The manual I'm seeing for that monitor online suggests that it only has a DB15 (VGA) input which means that it relies on you using a DVI to VGA adapter at some point. Is that adapter on the PC side or the monitor side? If you're using a DVI cable, does it have all the pins needed for VGA? (There will be a small cluster of four pins separated from the other pins by a gap, this is a "DVI-I" cable which is ever slightly more expensive to make than a "DVI-D" cable which omits them)

Of course I may have found the wrong manual in which case ignore.

Jedoc

It's got a DVI port as well as a VGA, so no adapters required. I'm at work, so I can't check the pins, but it also won't bring up any menus with the buttons on the front, whether or not it's plugged into the computer. So I think it's dead, Jim.