L1 DP1.4 KVM Issues with Mac Pro 2019 (Display constantly resets, going blank)


I just bought a Level 1 DP 1.4 KVM and I set it up yesterday. I got everything working except on my Mac Pro 2019 the screen goes black and resets on and off every minute or so. The monitor acts as though it is resetting and displays the “DisplayPort” overlay in the corner.

The computer works when plugging directly into the monitor.

I read on the product page that some thunderbolt 3 Macs have issues with the KVM where their signal strength isn’t enough and that it’s fixed by a DP repeater. Are the above symptoms indicative of that issue?

I figured I’d ask before buying something that wouldn’t solve my problem.



That sounds correct to me, there isnt a 1.4 repeater yet tho @wendell you have any timeline on that.

Amazon has a CableMatters DP 1.4 repeater that is cheap and doesn’t have the features of the L1 repeater, but maybe it’ll work for this case.


You can try that, Not sure if it would work or not with Mac tho so cant comment.

Yeah, I figure that’s a chance, but if it doesn’t work I can probably pick up a L1 repeater and just use it in 1.2 mode and give up HDR until there’s a better solution.

I’ve had some other reports of success on mac pro, are you using thunderbolt or dp? in one case, it was a bad thunderbolt cable… interestingly

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I’m using a TB to Display Port cable, Club-3D brand. I just hooked a different brand cable up and it hasn’t reset yet, so maybe that cable was the issue.

The cable that seems to work is “Maxonar” brand and was cheaper than the Club-3D one.

I’m excited to get this working. Having my Gaming PC and Mac on the same monitor frees up a lot of space on my desk. I also haven’t had any issues with my icons rearranging or anything, which I was worried about.

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might be a fake club3d haha :slight_smile:

Amazon really needs to axe 3rd party sellers or not carry any of the same products as theirs at the warehouse.

I have gotten fake “amazon basics” cables before, from amazon… which absolutely melted my brain

I’ve been using this “Maxonar” cable for a couple hours and not had an issue, so I would call that a success.

I wouldn’t know how to spot a fake Club3d cable, but I wouldn’t put it past Amazon nowadays to have such a thing.

Thanks for your help guys :+1:t2:, now I just gotta send this cable back.

You should send an email to club3d that you had a bad exp with their product not preforming, they might be able to help you out with that.


I would like to ask Club-3D why they don’t fix their shiddy DP 1.4-“HDMI 2.1-compliant” CAC-1085 dongle :-/

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