Microsoft Natural Ergonomic Keyboard 4000 v1.0 Caps Lock LED Won’t Turn On

Sometimes the issue might not come from the keyboard itself and may come from certain hardware and software faults.

• Restart your computer to fix any temporary software bugs.
• Try connecting the keyboard to another USB port. If it still isn’t working, try plugging it into another computer.

The LED not functioning may come from a fault with the key itself. The rubber membrane may be stuck down because of debris buildup, or wear-and-tear from extended use of the key.

• Try removing the rubber membrane and cleaning both contact points with an alcohol wipe, then dry them off.

If the issue persists, the rubber membrane may have lost its springiness, and you will need to replace it.

External damage and prolonged use may cause the LED to no longer turn on.

• Remove the LED and replace it with a fresh one.