Secondary monitor - suddenly no signal

[ilkill0128]

Hello,

Hardware: GTX-1080 Strix with a primary Dell-Monitor on the DisplayPort-connector and an old LG-Monitor on the DVI-D (using an active DVI-D to VGA adapter).

A few days ago the monitor didn't get any signal any longer. I checked whether the monitor works by plugging in my laptop to the VGA - works! I changed the adapter and unplugged the primary monitor - works! (with the old adapter this didn't work)

Today I tried to uninstall the NVIDIA drivers and change the BIOS-Setting from PEG to PCI but that didn't change anything.

The primary Monitor works without any issues. The secondary (LG) Monitor isn't registered at all - it only gets registered once I unplug the primary one.

Any suggestions would be much appreciated

 

[ilkill0128]

MERGED QUESTION
Question from ilkill0128 : "Secondary Monitor only works when primary is disconnected"

Hi

A few days ago my secondary monitor suddenly stopped getting registered and only displayed 'no signal'. I have a GTX-1080 Strix, the primary display is a DELL TFT S2716DG connected via DisplayPort. I had similar issues when I bought this monitor - back then IT wasn't registered, I had to disable the deep-sleep mode for it to work.

The secondary monitor is connected at the DVI-D port of the graphics card. Since it is an older model (LG BenQ G925HDA) it has a VGA input. So I got myself an active DVI-D to VGA Adapter. This adapter probably broke a few days ago (see below)
OS: Win7 Pro x64, BIOS up to date, graphics driver up to date (Nvidia 385.69)
Hardware: 550W power source, MB: Asus P8P67 LE, Intel i5 2500k

What I've tried:
- connected my laptop to the LG-Monitor to see if it works - it does
- unplug the primary monitor - this didn't change anything until I bought another active adapter to see if the one I have is broken -> desktop would show up on the LG Monitor, but signal is lost again when I plug in the primary monitor.
- reinstalled the Nvidia display drivers
- BIOS "graphics" settings changed from PEG to PCI (didn't change anything, will revert back to PEG now)

any suggestions/ help would be much appreciated
greetings

 

[ilkill0128]

So the answer was rather weird here. I got a replacement for the adapter I originally used - and suddenly it worked again for some reason. In what way these two adapters differ I honestly have no idea

original adapter:
https://www.amazon.de/gp/product/B01AU804HK/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

the other one (adapter works, but not for secondary monitor):
https://www.amazon.de/gp/product/B01DW2BJWU/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

thanks anyway, and sorry for the double post