Hey there. I’m an otherwise happy level1techs customer with a 5Gbps DP1.4 dual monitor KVM that’s been serving me well since the beginning of the year. However, recently I was trying to get a USB device to work and swapped a bunch of USB ports on my desktop, when I noticed that my KVM had stopped working! Both green lights are on, but there is no red light indicating an active PC, the physical switch button does nothing, and no HID keyboard shortcuts are working. Details below.
My setup. Note this was working perfectly until the issues I described began last week:
- Macbook Pro M1 plugged in to the KVM PC1 slots via an 8K-capable USB-C hub (with a couple USB3 Type A ports) and DP1.4 cable
- Windows PC with an ASRock motherboard and GTX1080 GPU plugged in to the KVM PC2 slots via a USB3 port on the back of the case and DP1.4 cable from the GPU
- KVM video output wired to a 144Hz 4K monitor via DP1.4 cable, plus my keyboard plugged in to one of the USB HID ports on the back of the KVM
Specifically, here’s the symptoms:
- Both green lights come on when the corresponding USB ports are plugged in, but no red LED indicating the active connection. (Unplugging a USB cable makes the corresponding green light turn off so it seems it can at least tell they are connected).
- Physical switch button is unresponsive
- The output monitor can tell the cable is plugged in, but thinks there’s no DP signal coming from the device.
- Neither the Macbook nor the PC lists the KVM as a display output, and neither lists it as a USB device / hub. Plugging / unplugging both the video and USB cables from both computers does not generate any “new device” sounds / notifications.
Here’s the troubleshooting steps I’ve tried:
- Unplugging all cables from the KVM (including power), waiting 10 minutes, and plugging them all back in
- Unplugging just the video cables (and just the USB cables) and plugging them back in
- Switching which of the two video ports I’m using (since it’s a dual monitor KVM and I’m only using one monitor with it at the moment)
- Plugging a different keyboard in and trying various combinations of keyboard shortcuts
- Switching which USB port the KVM is plugged into on both the windows PC and macbook
- Switching which USB HID port the keyboard is plugged into on the KVM
- Verifying that other devices are connected / powered when plugged into the same USB ports on the host devices
- Using a different keyboard with the KVM
- Pressing the physical switch button and KVM hotkey buttons on the keyboard in various combinations and successions
I also looked through the manual and searched these forums for similar issues, but turned up nothing. At this point I’m concerned that something malfunctioned inside the KVM, which would be unfortunate as I’ve only had it for a few months!
I had it plugged into an extension cord in a little mesh cable organizer under my desk and I must have knocked it loose while moving things around down there. Plugged it back in and made sure it was snug and it’s working perfectly again. Cheers!