Trouble connecting old iiyama monitor (DVI-I) to DisplayPort

[Tomaquet]

I’m having trouble connecting my new pc to an old iiyama monitor (AS4637UT BK) which I want to use as a second monitor along with my primary Benq monitor.

They both connected and worked fine with my old laptop using:
VGA out from laptop using VGA-DVI-A cable connected to iiyama
HDMI out from laptop using HDMI-HDMI cable connected to Benq

I have connected my new pc using HDMI to the Benq which works fine. I have also connected the new pc to the Benq using DisplayPort-DVI-D cable which also works fine. However, when I try to connect the pc to the iiyama (tried both DVI-I ports) using the DisplayPort-DVI-D cable the monitor is not recognised - the iiyama says “No signal”.

The iiyama monitor was given to me and the previous owner thinks he had some problem connecting to it using a digital signal (i.e. a DVI-D cable) so he had to use an analogue VGA-DVI-A cable but at the time didn’t know if the problem was the monitor or graphics card. It was a long time ago so can’t remember clearly.

So on this assumption (that the iiyama monitor would only accept an analogue input), I bought a DisplayPort-VGA adapter so that I could connect the pc using the adapter with a VGA-DVI-A cable. However the monitor is still not recognised. I then connected the DisplayPort-VGA adapter to the Benq monitor using a VGA-VGA cable and the Benq wasn’t recognised either. I guess this would imply that the DisplayPort-VGA adapter doesn’t work, does it? (The VGA-VGA cable works from my old laptop to the Benq so the cable is fine).

I’m not sure what to try next – I could buy more cables and adapters but I’d like to confirm there is nothing else I’m missing:

Is there anything in the BIOS I should be changing/enabling?
Is it possible that DisplayPort only outputs a digital signal?
Am I correct in assuming the DisplayPort-VGA adapter converts the signal to analogue?
Is it likely that the digital part of the iiyama is broken (on both inputs) but the analogue part works ok?
What other incompatibilities exist between motherboards and monitors?

Thanks for any help offered!!


iiyama inputs – 2xDVI-I
Benq inputs – 1xHDMI, 1xDVI-D, 1xVGA
(New pc, windows 10, i5 6600k) Asus Z170i – 1xHDMI, 1xDisplayPort
(Old laptop) Acer Aspire – 1xVGA, 1xHDMI

HDMI-HDMI cable
VGA-DVI-A cable
VGA-VGA cable
DisplayPort-DVI-D cable
DisplayPort-VGA adapter

 

[Tomaquet]

I’m having trouble connecting my new pc to an old iiyama monitor (AS4637UT BK) which I want to use as a second monitor along with my primary Benq monitor.

Well I tried the DisplayPort-VGA adapter at a friends house and it works fine so I'm completely confused as to why it doesn't work with either of my monitors.

Is there some problem "handshaking" between the monitor and the pc? (because the adapter prevents it - I guess once the signal is converted to VGA there can't be any communication from the monitor to the pc)

Any help would be most appreciated - I'm tearing my hair out with this problem!

EDIT: I've just read that skylake chips don't support VGA. Does that mean my VGA monitor won't work with an adapter?

 

[Tomaquet]

Well just for completeness sake, I'd thought I'd better reply what I've discovered.

According to Asus, no VGA-only monitor will work with skylake chips even with an ("active") adapter. However, some skylake motherboards have included a specific chip which does allow VGA monitors to work. In my case (Asus Z170i), that chip isn't there so no VGA for me.