Both the AudioVision 14-inch Display and the AppleVision 1710 AV Display have their own processor chip which receives signal through the ADB channel in the monitor cable. Restarting the computer may not clear the chip. The following steps should clear up this situation and restore the proper control panels settings and functionality:
1. Shut down the computer and monitor. Wait 30 seconds.
2. Double-check monitor cable(s) for proper connection(s). Because the ADB signal is used by the monitor and the computer to determine configuration, you should connect the ADB devices this way: mouse to keyboard, keyboard to monitor, monitor to cpu.
3. Next power up the computer first, and THEN the monitor.
4. If problem remains, reset the PRAM by restarting the machine and holding down the CMD-OPTION-P-R just after you hear the startup tones, and let go as soon as you hear them again.
5. If problem still remains, system software (which includes the proper AV software) may be at fault. Options are to custom reinstall AV software or, follow steps for a clean install of system software on page 7 of "Additional Tips & Troubleshooting" addendum for Power Macintosh manuals.
The Video Control panel provides software control for brightness and contrast on the AudioVision 14-inch Display with System 7.1. In System 7.5, this control panel is replaced by the AppleVision Setup control panel which works on both AV monitors.