AppleCare Tech Info Library -AppleVision 1710/1710AV: Black Screen, Distortion, or Misconvergence Caused by CRT Arcing (5/97)

TITLE

AppleVision 1710/1710AV: Black Screen, Distortion, or Misconvergence Caused by CRT Arcing (5/97)

Article ID:
Created:
Modified:

21128
3/21/97
5/14/97

TOPIC

I have an AppleVision 1710 display which appears to have a distorted image on the screen. I have not been able to reset the image using the front panel controls.

DISCUSSION

On a limited number of AppleVision 1710 monitors, an internal arcing within the cathode ray tube (CRT) may reset some control values in the monitor's internal microcontroller chip. This can cause the screen to go blank, cause some geometry distortion, or cause the convergence to become intolerable.

The monitor is most likely to experience this problem within the first few hours or days after installation. However, it is possible to have this problem anytime during the life of the product.

CRT arcing is normal and expected on a certain percentage of displays from all manufacturers. An arc happens when residual particles inside the CRT are dislodged. This usually occurs when the display has experienced physical vibration, as (for example) during transportation. The arc time is short and there is no safety hazard because the arc is contained inside the sealed glass of the CRT. This arcing will not cause permanent damage to the display.

Solution:

In some cases, you can eliminate the distortion simply by cycling power (turning the display off and then on again) using the power switch on the front panel of the monitor.

If that does not solve the problem, shut down the monitor and unplug the power cord and ADB cables from the back of the monitor. Count to ten. Then plug in the power cord and ADB cables. This action should remove all symptoms. If the blank screen symptom persists, contact Apple Technical Support.

Document Information
Product Area:	Monitors-Displays
Category:	Multiple Scan Displays
Sub Category:	AppleVision 1710; AppleVision 1710AV