H132433 - 6553 MONITOR - 2401 POST ERROR WITH DDC ENABLED                      
                                                                                
 SYMPTOM:                                                                       
 A 2401 POST error codes may be experienced on systems which have               
 6553-503 monitors attached.                                                    
                                                                                
 PROBLEM ISOLATION AIDS:                                                        
 Only 6553-503 monitors, in serial number range 2300001 to                      
 2308886 are affected.                                                          
                                                                                
 FIX:                                                                           
 A limited number of 6553-503 monitors have been distributed with               
 a wrong DDC check sum code.  This can result in a POST (Power-                 
 On System Test) error on systems that support DDC, if the DDC                  
 function is enabled in the system unit.                                        
                                                                                
 Temporary work-around:                                                         
 The monitor and system will function normally if the DDC                       
 is disabled.  This can be done in the Video Setup section                      
 of the BIOS (Basic Input-Output System).                                       
                                                                                
 Having disabled DDC, to ensure flicker free operation the                      
 following refresh rates should be entered in the Video Setup                   
 section of the BIOS:                                                           
                                                                                
  Set the monitor type to:  Custom                                              
                                                                                
  Set    640 by  480 to:  85Hz                                                  
  Set    800 by  600 to:  85Hz                                                  
  Set   1024 by  768 to:  75Hz                                                  
  Set   1280 by 1024 to:  60Hz                                                  
                                                                                
 An engineering investigation is currently in progress.  A                      
 permanent solution for the problem is being formulated.  This                  
 RETAIN tip will be updated when the final fix is available.                    
                                                                                
 Jan. 29, 1996