Question Can't use an HDMI Switch on a LG C1, it works but won't load Windows

[Nachmanowicz]

So I have a weird problem. I have a Neo Qled QN90C in my bedroom as a monitor and a LG C1 in my living room. I drilled a hole in the wall to pass cables through.
All my troubles stem from the fact that my MSI RTX 4080 has only one HDMI out. I thought it wouldnt be a problem, a DP to HDMI adapter would solve it no easy, right? Wrong. Nothing works properly, I even bought expensive adapters with chips but they also didn't work consistently. So I thought, since the displays are in different rooms, I will never use them at the same time, so I can just use an HDMI switch, right?
And it does work on my monitor TV, but on the C1 it just won't load into Windows. Ill get the mobo splash screen and windows loading. I can get to Windows on safe mode, but regular windows, I can't even get to the password screen. Screen will just go black every time! Plz help =( Changing cables everytime is so, so bad.

 

[KingLoki]

The C1 has one rear and 3 side hdmi ports. Have you tried plugging into every port on the tv and also try the other DP ports on the 4080 card?

 

[Nachmanowicz]

The C1 has one rear and 3 side hdmi ports. Have you tried plugging into every port on the tv and also try the other DP ports on the 4080 card?

It's a HDMI splitter, it uses only the one HDMI out on the 4080.
Now I haven't tried all the HDMIs on the C1, it's an easy try... will do.

 

[KingLoki]

When you try each one, reboot pc and power tv off/on each time too.

 

[Nachmanowicz]

When you try each one, reboot pc and power tv off/on each time too.

Yes, I've been always doing it

 

[KingLoki]

👍

 

[KingLoki]

As a troubleshooting measure, if you can, just run the display port-hdmi cable direct from the pc to the C1 to see if the switch is the problem if nothing else works.

 

[SyCoREAPER]

The C1 is a PITD when it comes to external sources. It hates my Onkyo, it has a hard time with resolution switches.

That said. This sounds like a probable driver issue. SafeMode is well SafeMode, it loads as few resources as possible including drivers.

Check your refresh rate. My assumption is a refresh rate is being put out by Windows that the switch can't handle. IIRC, with the lack of drivers loading, SafeMode defaults to either 30 or 60hz. Regular Windows could be trying 119.xx or 120hz and your switch simply can't do it.

Alternatively, there are C1 Drivers which I don't think that will help at all with your drivers. I don't remember where I found them, it was was on some random LGs other countrie download page.

 

[Nachmanowicz]

As a troubleshooting measure, if you can, just run the display port-hdmi cable direct from the pc to the C1 to see if the switch is the problem if nothing else works.

I tried all the HDMI inputs on the TV, xcept the one that I couldnt use anyways cause its Arc with the same result.
And Im not using displayport to HDMI, I'm using HDMI splitter.

The C1 is a PITD when it comes to external sources. It hates my Onkyo, it has a hard time with resolution switches.

That said. This sounds like a probable driver issue. SafeMode is well SafeMode, it loads as few resources as possible including drivers.

Check your refresh rate. My assumption is a refresh rate is being put out by Windows that the switch can't handle. IIRC, with the lack of drivers loading, SafeMode defaults to either 30 or 60hz. Regular Windows could be trying 119.xx or 120hz and your switch simply can't do it.

Alternatively, there are C1 Drivers which I don't think that will help at all with your drivers. I don't remember where I found them, it was was on some random LGs other countrie download page.

The switch cant handle it. It can run 144Hz 4k with VRR and HDR. Right now I'm thinking the most probable cause is the dimnished power output from the switch is not enough for the 5 meter HDMI 2.1 cable to run the specs it is supposed to....

 

[KingLoki]

But does the C1 work when directly plugged in from the C1 hdmi to 4080 display port with the cable you have?

 

[SyCoREAPER]

The switch cant handle it. It can run 144Hz 4k with VRR and HDR. Right now I'm thinking the most probable cause is the dimnished power output from the switch is not enough for the 5 meter HDMI 2.1 cable to run the specs it is supposed to....

Assume you meant can handle.

It's possible your exceeding the signal and a repeater may be needed but I've run 2.1 (real spec) behind 5 meters but YMMV.

Rereading the OP I'm now questioning and not understanding, why not run HDMI to the TV which the TV won't complain about and DP to the monitor?

You can also try (link is down and I'd post drivers but never trust drivers from strangers) https://www.lg.com/html/support/software-drivers.html

Scroll midway to 'Windows Monitor Drivers', click See More and select 'Ultra HD - 4K Windows'. IIRC it includes a driver that Windows will recognize the LG display and I think it includes a color profile but can't remember.

If all that fails, Safe Mode, DDU, reinstall the Nvidia driver. Use the imminent to be official but will be the official replacement that's currently in Beta but fully stable to install the drivers.

Download GeForce Experience - Beta

Get early access to new features ahead of public release<br/>

www.nvidia.com

If direct cable connections don't work your card may be in trouble.

 

[Nachmanowicz]

Assume you meant can handle.

It's possible your exceeding the signal and a repeater may be needed but I've run 2.1 (real spec) behind 5 meters but YMMV.

Rereading the OP I'm now questioning and not understanding, why not run HDMI to the TV which the TV won't complain about and DP to the monitor?

You can also try (link is down and I'd post drivers but never trust drivers from strangers) https://www.lg.com/html/support/software-drivers.html

Scroll midway to 'Windows Monitor Drivers', click See More and select 'Ultra HD - 4K Windows'. IIRC it includes a driver that Windows will recognize the LG display and I think it includes a color profile but can't remember.

If all that fails, Safe Mode, DDU, reinstall the Nvidia driver. Use the imminent to be official but will be the official replacement that's currently in Beta but fully stable to install the drivers.

Download GeForce Experience - Beta

Get early access to new features ahead of public release<br/>

www.nvidia.com

If direct cable connections don't work your card may be in trouble.

The problem is, its not a monitor, it's a TV. I use it as a monitor, but its a Neo Qled QN90C 43", so it doesnt have a DP in. My whole problem is I have two HDMI 2.1 displays for only one HDMI out. The best I could muster with a DP to HDMI adapter with a chip and all was get 120Hz on my QN90C instead of the 144Hz.

But does the C1 work when directly plugged in from the C1 hdmi to 4080 display port with the cable you have?

Yes, if I plug the C1 to the 4080 directly it works like a charm, even sending 5.1 audio signal via ARC to the receiver...

 

[KingLoki]

Why not run two seperate cables then and select the monitor/tv you want in windows display settings for dual monitors or nvidia control panel

 

[KingLoki]

Use two hdmi to display port cables plugged into the 4080??

 

[SkyNetRising]

My whole problem is I have two HDMI 2.1 displays for only one HDMI out.

Get graphics card with two HDMI out ports?
ASUS TUF Gaming GeForce RTX 4080 - has two HDMI out.

May be even upgrade to 4090.
ASUS TUF Gaming GeForce RTX 4090 OC - also has two HDMI out.

 

[KingLoki]

But the one hdmi out is because of the switch insn't it? Why not run them as dual display with two cables and select the display on pc, instead of a working switch?

 

[Nachmanowicz]

Get graphics card with two HDMI out ports?
ASUS TUF Gaming GeForce RTX 4080 - has two HDMI out.

May be even upgrade to 4090.
ASUS TUF Gaming GeForce RTX 4090 OC - also has two HDMI out.

Brother I live in Brazil, these things are expensive lol, I can't be just buying another high end card like that. Having said that I might buy a 5090 when it comes out... and it better have 2 HDMI outs. lol

Kingloki, I can't run them as dual displays because I only have on HDMI out my man. And the display port to HDMI cables and adapters I've tried (which were many) never fully work. They're either giving me lower frequencies, no VRR and HDR support, etc.

 

[SyCoREAPER]

The problem is, its not a monitor, it's a TV. I use it as a monitor, but its a Neo Qled QN90C 43", so it doesnt have a DP in. My whole problem is I have two HDMI 2.1 displays for only one HDMI out. The best I could muster with a DP to HDMI adapter with a chip and all was get 120Hz on my QN90C instead of the 144Hz.

To be honest I didn't look up the "monitor" just assumed it was a true monitor. That being said, you have a 4080, I have a 4090, how often do you actually even make it past 120 of at all? I know I sure as h3ll don't. Plus the TV is only 120hz. That means you need push the GPU harder just to run on one display and are wasting headroom because of the TV.

My recommendation is set up your games for whatever target, let's say 120fps, you don't have to let your eyes adjust to the frame rate (but will for latency either way), you're not wasting performance and are extending the life of the card because you can undervolt (or just not push it to 144fps) and you've solved the whole no signal issue.

I get it, you have 144hz display and want to take advantage of it but you aren't gaining much, if anything perceivable with 22 extra frames of your eyes will be seeing 120 on the TV.

Just my opinion.

 

[Nachmanowicz]

Ah man I can't do that, I need my 144Hz! My monkey brain won't allow me to settle for anything less. After all, I paid for it! My card is already undervolted. And even that one DP to HDMI 2.1 @120Hz adapter I got wasn't fully functional. I'd get the occasional artifacts and some black screens for a second or two.

 

[Lolomid]

connection problems, incorrect HDMI input, outdated display drivers, Some HDMI switches may not work with specific devices or displays due to differences in resolution, refresh rate

 

[gamerk316]

As a C2 owner (and previous B6 owner), one thing I will note is LG TVs can get *really* confused about some resolution modes. As an example, it won't auto-detect DOS resolution modes unless the display is already on. [EG: If I turn off my PC during a memory test, it won't pick up the resolution and remain blank]. I've seen one or two instances where it fails to pick up the Windows resolution, but those are exceedingly rare.

What resolution are you running your desktop? More importantly: In the NVIDIA Control Panel, are you using a resolution under the "TV" resolutions, or one of the PC ones? I ask because there are color space/mapping concerns that could be causing you some headaches with the TV as well.

 

[Nachmanowicz]

As a C2 owner (and previous B6 owner), one thing I will note is LG TVs can get *really* confused about some resolution modes. As an example, it won't auto-detect DOS resolution modes unless the display is already on. [EG: If I turn off my PC during a memory test, it won't pick up the resolution and remain blank]. I've seen one or two instances where it fails to pick up the Windows resolution, but those are exceedingly rare.

What resolution are you running your desktop? More importantly: In the NVIDIA Control Panel, are you using a resolution under the "TV" resolutions, or one of the PC ones? I ask because there are color space/mapping concerns that could be causing you some headaches with the TV as well.

Well, its hard to tell since I can't even reach windows on it.
It might be that the cable doesn't have enough juice to power it with the lower power the switch can give. I bought a fiber optic HDMI 2.1 cable and I'll try it, waiting for it to arrive.

 

[gamerk316]

I brought a couple of monoprice 2.1 cables; never had an issue with them.

 

[Nachmanowicz]

It was the cable. I bought a 20 meters (overkill) fiber optic cable and it worked!!!

But I'm getting some quick blackouts and glitches for half a second quite often. Could it be the way the cables are folded? Should I get a shorter fiber optic cable?