Check the batteries in your calculator. As the batteries age, the TI-86 automatically adjusts the brightness level to accommodate for the reduced power, meaning that the display will dim over time. Fully charged batteries will give you the maximum control over the fade level of the display.
Turn on the calculator. If the calculator is not already on the home screen, press the "exit" key. Enter a few digits on the home screen to provide a frame of reference while adjusting the fade level.
Press the "2nd" key, the yellow key located in the upper left-hand corner of the keypad. This key is used to access the secondary functions of the other keys on the keypad.
Locate the navigation arrows in the upper right-hand quadrant of the keypad. To increase the fade level of the display, press the down arrow on the display. Press the up arrow to reverse the change. Because the TI-86 adjusts brightness in small increments, you may need to press the up or down keys more than once.