Fujitsu Lifebook AH550 - Hard Drive;Optical Drive Access Indicator; Numlk Indicator; Capslock Indicator; Scrlk Indicator

23 - Status Indicator Panel
Hard Drive/Optical Drive Access Indicator
The Hard Drive/Optical Drive Access indicator glows green when your internal hard drive is being
accessed. Note that flickering is normal.
NumLk Indicator
The NumLk indicator states that the integral keyboard is set in ten-key numeric keypad mode. 
CapsLock Indicator
The CapsLock indicator states that your keyboard is set to type in all capital letters. 
ScrLk Indicator
The ScrLk indicator states that your scroll lock is active.