Dell KVM issue

[netdudeuk]

Hi

I've just installed the Dell P3421W with a desktop PC on the HDMI port and either my 2017 MBP (with macOS Monterey) or my new Thinkpad T14 on the USB-C port.

Both laptops charge ok and the 4K native video also works ok and looks good for what I need.

The built-in Dell KVM has my Corsair keyboard and SteelSeries mouse on the inputs. Switching the video input also switches the input devices but although there are no issues with the T14 and my desktop PC), there's an issue with the MBP where the keyboard and mouse become unusable immediately or soon after changing to them.

The lights are off on both the keyboard and the mouse when switched to the MBP.

Dell DDM isn't supported for my MBP / monitor combination. However, it shouldn't be needed to switch USB inputs as I've configured the monitor to do this.

Please does anyone have any ideas about how to fix this ?

Thanks

 

[satcomer]

How much power does power supply have? It could be the limit and only one device at a time!

 

[netdudeuk]

How much power does power supply have? It could be the limit and only one device at a time!

Thanks for the reply.

Dell says 'Power Delivery up to 65 W'. Apple says that my MBP comes with a '61W USB-C Power Adapter'.

There are no issues with the T14 when that's connected to the USB-C port on the monitor.

 

[satcomer]

Yes but in requires power to put the display onto the screen! That could knock the power down!

 

[netdudeuk]

I've also plugged a charger into the MBP with no improvement.

 

[ikkysleepy]

Any updates on this? Did it end up working with the latest Apple OS update?

 

[netdudeuk]

Any updates on this? Did it end up working with the latest Apple OS update?

I bought a couple more cables and settled on this one -

Cable Matters 5 Gbps USB C to USB C Cable with 4K Video Resolution Support and 100W Power Delivery - 1.8m

I may have to plug in and out a couple of times but then I'm good from then on. Same applied for the T14.