AST RESEARCH, INC.        TECHNICAL BULLETIN # 1557          08/30/96 
 
 
 
TITLE:  Video Refresh AST 20H Monitor, Bravo
 
 
SUMMARY 
 
   The AST 20H monitor screen may experience gray shading over the 
   entire screen when connected to a Bravo MS-T P200 system. 
   This issue affects any system that uses the ATI Mach 64 chip with 
   the specific monitor mentioned above.    


ISSUE 
 
   A Bravo MS-T P200 system, AST part number 503058-003, connected 
   to an AST 20H monitor, AST part number 501328-002, may experience 
   incorrect video. The problem may be most evident when a screen is 
   displayed with a white background. Gray shading may be seen over 
   the entire screen instead of the normal white background expected.    

 
BACKGROUND 
 
   When a Bravo MS-T P200 uses the ATI video driver at a resolution 
   of 640 X 480, the refresh rate is set by default to 120Hz . 
   The timing specification of the AST 20H has a maximum recommended 
   refresh rate of 72 Hz at this resolution.    

 
ACTION 
 
   1. Open the Control Panel in Windows 95 and double-click
      on the Display icon.
   
   2. Select the Adjustment tab.
   
   3. Click on Change Refresh Rate and set the refresh rate 
      from 120 Hz to 70 Hz and click on Change.
   
   4. Select OK and answer OK to Save Settings.    

 
NOTES 
 
   N/A    

 
TAN 000951CH 
 
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