Gentlen KVM Switch DVI 4 ports Auto-Scan Support Windows, Linux, MacOS9 / OSX, Sun Micro System

Review for4 ports USB DVI KVM Switch Auto-Scan Support Windows, Linux, MacOS9 / OSX, Sun Micro System by Ureru.Bought this to replace an older ATEN VGA KVM which still worked but would not support the new nvidia 1080 graphics card.In the box you get one KVM, a single A4 sheet of instructions and two power adapters. One UK power adapter and one 2 Prong adapter (not UK).Build quality is excellent, all metal construction on the KVM.There are no DVI cables and no USB type AB cables. I had to buy them separately.I connected 3 PCs to it over DVI.One work PC with onboard graphics,A gaming PC with nvidia 1080 graphics card andone basic desktop with ATI radeon graphics card.Everything worked. I can switch between the PCs by pressing the buttons on the front of the KVM or using a keyboard shortcut. The KVM makes a loud beep when switching between PCsI was very happy with it as it jumped between the PCs without any real delay and mouse and keyboard worked fine without lag.I shut all the PCs down, came back to it later in the day, turned on my PCs and found nothing worked.While all lights on KVM were on it wasn’t switching either from the buttons or via keyboard.I went through the troubleshooting as described on the information sheet but it still would not work.I disconnected all the PCs from the KVM and tried them directly with monitor and keyboard/Mouse, all worked.I shut them all down, reconnected them to the KVM and tried again. Still nothing.I returned it for a refund.