Why Do Two Keyboards Fail While a Third Works on the Same PC?

Test the working keyboard in every USB port, preferably the rear motherboard ports and not a hub. Then test the other keyboards using those same ports, one variable at a time. If only one port fails, check for physical damage and USB power-management settings. If the problem follows a particular keyboard, try another data-capable cable and check whether its controller or cable is failing.

For the RK96 and RK-S98, verify the physical connection mode and make sure they’re actually set to wired mode when plugged in. Also check the battery, wireless receiver, and cable. Some USB-C keyboards can be picky about cables or USB-C-to-USB-A connections, so try a known-good data cable and, if possible, USB-C-to-USB-C. Testing them on another system should quickly show whether the issue is with the keyboards or this PC.

A powered USB hub can be useful as a quick test, especially if the keyboards draw more power during startup. If devices repeatedly connect and disconnect, watch Device Manager while plugging them in. That can point to unstable USB power, a driver problem, or a grounding issue rather than simple keyboard compatibility.

Try a keyboard from a completely different brand first. Since the two failing models are related, the problem may be specific to their firmware, controller, or compatibility rather than the motherboard. Also test each keyboard on another computer or in the BIOS/UEFI. If they work there but not in Windows, remove the keyboard devices in Device Manager and let Windows detect them again.