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The Level1Techs KVM (Keyboard, Video Mouse) Switch - 4k/60hz monitor & USB Switchbox | Level One Techs


#201

@wendell, got the displayport to HDMI adapter in for console out to the second screen-

The monitor says no input detected- but the Nvidia control panel and windows sees the monitor. For a sanity check on the adapter, GPU and cables I un-plugged the second monitor console output using the adapter from KVM and ran it strait from the GPU and the second display works.

Maybe another brand would be better? Or maybe displayport to DVI? Or am I going about this all wrong?


#202

So I tried a Dell Displayport to DVI adapter, still no joy.

Nvidia control panel can see the second monitor, lists it as Asus VH236H, but the monitor says there is no input. This is with both the DP to HDMI, DP to VDI, and for fun I even daisy chained and went DP to VDI to HDMI to VGA (combo sandwich of adapters) and control panel still shows Asus VH236H, but no display/no input according to the monitor.


#203

Still working on it. I found one vga to dp adapter that will work. Hdmi to dp is another matter entirely. And dvi is possible if I sort out hdmi…


#204

Have the DP to VGA adapter model? I’m game to Amazon it asap haha.


#205

@wendell I have a weird bug as well. I have the 4 port/2 displays model and 2 computers hooked up to it.

Computer 1 has a 1080 Ti and Computer 2 had a RX 580. All was fine, I just swapped out the RX 580 for a 1070 and now only 1 monitor will work reliably. Randomly the second one will show up but it soon crashes the entire machine. If I plug it in directly everything is stable.

Computer 1 is stable regardless. I’ve swapped out cables going from the KVM to computer 2 with brand new ones. Any ideas?


#206

What monitors? Updated the Nvidia dp firmware?


#207

oh well, that makes me feel dumb. I didn’t know that existed. Updated the firmware and now it behaves just fine. While I have you here can I ask about another edge case?

I moved my RX 580 into a sonnet breakaway box to use with my MacBook Pro 2016, if I route the display through the kvm, they can’t make a good connection. If I route them through directly to the monitor they work just fine. Any ideas?


#208

Cables or grounding can be the issue there. 19 pin not 20 pin dp cables are a must. Try to touch the metal outside of the laptop to the metal case of the thunderbolt enclosure.

I gotta make a list of known good USB c to dp options because they are few. Tb docks with a dp socket seem to work best.


#209

I’m just plugging it into the RX 580 inside the enclosure. Tried a bunch of different thunderbolt ports and found a combo where one monitor works :).

So far so good, happy to help you debug if you want to go down this rabbit hole with me


#210

@wendell, what model is the DP to vga adapter?


#211

Still testing


#212

Tendak vga to hdmi


Plus

Works up to 1920x1080

The USB power is the giveaway here


#213

@wendell oops, I’m trying to go the other way, take the DP out of the kvm console output to a monitor’s HDMI (or dvi or vga). This would get my second monitor going for my desktop and work laptop. For my t420 I would need a dvi to DP adapter like the ones you listed (USB power input) or in this case go with a known working adapter you linked taking vga to DP


#214

If you want to connect an HDMI monitor to the console port on the kvm, an HDMI based kvm may be a better choice. Display port is the most functional display interface tech. It’s probably impossible to do dp out of the kvm to vga since it’s designed for 4k.

I could maybe see the case for a universal kvm that accepts everything from vga to dp inputs for dp output which is what these adapters would give you.
Do you not have a dp monitor to use with the output?


#215

@wendell yeah unfortunately the second monitor only has HDMI, dvi and vga for input, my newbness I thought of display outputs more like UDP and not TCP.

The primary monitor is the LG 43" 4k, so it’s just me being greedy and trying to get even more realesate in, but I would have been fine with the single display lvl1 kvm with just the 43".


#216

Are there any DP extenders/repeaters that have been tested and work with your KVM?
I’ve got one working (link here) between the KVM output and the monitor.
When trying the repeater on one of the KVM inputs with a Linux machine, it works initially, but the machine seems to lock up once you switch to another input. The monitor goes into power save mode and the keyboard is unresponsive (caps/num lock not working).


#217

So I’ve run into an issue with this KVM. I’ve been building a new machine; it’s a Linux development workstation, so I only got a Radeon RX 550 for a video card (the GV-RX550D5-2GD from Gigabyte). I have it hooked to port 3. 1 is my current Linux laptop, 2 is my Windows gaming laptop.

If I boot with the KVM on port 3, the console comes up, and everything is good. If I switch to another machine and then back, I get a blank screen and no signal. This happens if I’m in X on a Gentoo LiveCD, the console without X, or even in the BIOS/UEFI setup screen.

I’ve tried switching virtual terminals, logging in over SSH and restarting X remotely, etc. Nothing works except rebooting the machine.

Are there any known issues with Gigabyte Radeon cards? I have the dual monitor version, but am only using one of the two DisplayPorts (the lower one).


#218

No but check kernel/log messages. Maybe you are getting dp link failures? What kernel bersion? Strongly recommend a recent kernel version because of changes to amdgpu. 550 is newer silicon iirc.


#219

I have a test one from china but still trying to find one that does 21:9 and 32:9 resolutions.

What’s your setup you need a repeater?


#220

I have 2 laptops and 2 servers that need connecting to the KVM. The servers are in a different room, requiring a 7m cable run for connectivity. The laptops were in the office.
I’ve since moved the KVM and laptops to where the servers are and used the extender on the DP output of the KVM - this works really well at 3840 x 2160 60HZ resolutions on my Dell UP3216Q.
The problems I was having was using a DP repeater on the KVM inputs.