If the keyboard doesn't accept any input, troubleshoot the problem by first verifying that the cable is connected to the computer. Consider trying it on a different device to see if the problem is due to the keyboard or the computer itself. In some cases, cleaning the keyboard helps.
Before attempting to clean or repair a keyboard, make sure to disconnect it completely from the computer. To clean a keyboard, start by turning it upside down and gently moving it to dislodge any crumbs or other stuck particles. Use cans of compressed to remove smaller items. If your keyboard has removable key caps, remove them, and check the area underneath for signs of damage.