By methodically troubleshooting factors like cabling, power, input/output settings, and software, we can diagnose the root cause of the HDMI splitter failing to be recognized. They work by taking the signal from one Ethernet cable and splitting it into two or more lines. This is helpful when you have limited ports or. They are used to split one network signal into multiple signals. HDMI splitters are great tools for duplicating HDMI signals to multiple displays, but they can come with some common issues.