Display over USB stopped working.

[RovakX]

Hi all,

 

I cannot get my display over USB-C working.

 

Some background: 

I've got myself a shiny (second hand new) Dell XPS 15 7590.

I'm coming from a Dell XPS 15 9560, which was fine untill I trashed it with coffee.

 

I have a Gigabyte M27F display with KVM switch; DP is connected to gaming rig, USB-C is connected to work laptop.

This was awesome with my previous laptop; plug in usb C for work, unplug it for gaming, one keyboard and mouse to rule them all.

 

So, I just swapped laptops, kept all the cables the same, but cannot get the display over USB-C working. It worked so well with the previous Dell.

(HDMI output works fine tough, so I don't think it's a GPU hardware issue, good assumption?)
The laptop charges over it, accepts the KB and mouse, and everything seems to work, but the screen stays black and says "No-signal".

Even in windows: the screen is there both in widows Display settings and in the Intel Graphics Command centre.

Refresh rate was set to 59, changing this does not seem to impact it. There are no other options as far as I can see.

 

I think I've got all drivers up to date.

Got the Geforce experience, did the Dell update, and the Intel Driver support assistant. Even via the windows control panel I tried updating drivers.

(This actually rolls back the intel driver, which Intel Driver support assistant then wants to update agian.)

Today I tried at work with one of those Dell USB-C docking stations, and with a Dell U2721DE. These both worked just fine! Why? How? I don't understand.

 

Is there any additional info I can help you out with? So you can help me out...

I will bake you a cookie if you can help me! 

 

Cheers,

Me

[Moonzy]

does it say it suports DP pass through on the type-c port? if it doesnt then it wont work

type-c doesnt necessarily mean it carries display signals

[RovakX]

The Dell XPS 15 XPS 7590 supports DisplayPort 1.2 I believe.
Anyhow, the XPS 7590 laptop works flawless with the U2721DE displays at work, and my M27F display worked flawless with the XPS 9560, an older model. So both parts seem compatible to me, but together they sport this weird behaviour. 

[Moonzy]

3 hours ago, RovakX said:

The Dell XPS 15 XPS 7590 supports DisplayPort 1.2 I believe.
Anyhow, the XPS 7590 laptop works flawless with the U2721DE displays at work, and my M27F display worked flawless with the XPS 9560, an older model. So both parts seem compatible to me, but together they sport this weird behaviour. 

hmm... tried different cable? the cable might work in other matches but no harm trying another cable

 

i've no clue other than that

[RovakX]

Dear Moonzy, Thank you for the replies. 

I did not have a different cable laying around of which I was sure it supports display signals.
I will borrow one today at work and will try a different cable later when I come home. 

I'll keep you posted. 

 

(haha silly me, what I did try once was truning the cable around. I do know when messing wih dapter cables (which I am not, but still) or in the old anaog days, that directional cables were a thing. So I thought, sure no harm in trying... but to no avail, obviously.)

 

[RovakX]

So yes...
I got a new cable. That fixed it.

Can someone explain this to me? How did my cable work with my old XPS and not with this new one?
Did I break the cable just as I installed the new laptop for the first time? What are the odds of that?

 

Is there some kind of cable tech that I am unaware of? A tech that allows older systems to send a display signal through it, but it doesn't work on newer ones?

Any cable experts here?  

 

It's solved anyway, but still, I'd like to know.

 

Cheers!

[Moonzy]

1 minute ago, RovakX said:

So yes...
I got a new cable. That fixed it.

Can someone explain this to me? How did my cable work with my old XPS and not with this new one?
Did I break the cable just as I installed the new laptop for the first time? What are the odds of that?

 

Is there some kind of cable tech that I am unaware of? A tech that allows older systems to send a display signal through it, but it doesn't work on newer ones?

Any cable experts here?  

 

It's solved anyway, but still, I'd like to know.

 

Cheers!

If I had to guess, the old cable was either on the edge of stability and on your new setup it just wasn't good enough, or the variance in connector size affected the contacts slightly, causing the signal to not go through (I've experienced this more on micro USB rather than type C)

 

Either way, glad it's resolved