Apple Macintosh PowerBook 190 Series - Manual (Page 106)

A key won’t stop repeating.
m Open Key Caps in the Apple (K) menu. If any keys in the window are
darkened, keys may be stuck down on your keyboard. This problem is
sometimes related to an incorrectly installed RAM expansion card. Review
the RAM card installation instructions in Appendix C.
PowerBook display
The screen went blank.
m Screen dimming may be on. Move the pointer to restore the
screen’s brightness.
m The computer may have gone to sleep. Press any key (except Caps Lock)
on the keyboard to wake it.
m The battery may need recharging. Plug in the power adapter, let the
battery charge for a few minutes, and then try to wake or start up the
computer again.
The screen flickers.
m Adjust the brightness control (¤) and the contrast control (O) to the right
of the display.
m Open the Monitors control panel and set the computer to display fewer
colors or grays.
m If tilting the display affects the flickering, there may be a loose cable.
Contact an Apple-authorized service provider, or call the Apple
Assistance Center.
The computer freezes when screen dimming takes effect.
m Screen dimming does not work with some programs. Open the PowerBook
control panel and turn off screen dimming.
99 Tips and Troubleshooting