Hello,
I have Razer laptop Blade 15 base 2021 model RZ09-03519. Various keys stopped working. Uninstalling the Windows 10 keyboard drivers and reinstalling didn't work. I replaced the keyboard/palmrest assembly and all keys worked but keyboard illumination didn't. 2 days later illumination works but now 4 other keys aren't working. It's obviously a software issue ( no viruses found using Norton scan). Device Manager shows 2 identical HID keyboards even though no external keyboard is connected. Looks like the previous keyboard wasn't faulty at all.
Windows is updated and Synapse says this ensures Razer drivers are up to date. Keyboard settings in Windows are correct and Win keyboard troubleshooting finds no errors. I find Synapse 3 about as easy to use as a Chinese instruction manual. I would be very grateful for some advice on how to fix the problem. An external USB keyboard and MS virtual keyboard both work correctly.