Acer AC501 AC501 Monitor Service Guide - Page 20

K. Digit Control Digit control circuit includes micro processor U2(UMC6861), EEPROM IC(24LC04). With t he program, u-P control all the functions of the monitor. User can control t he functions and all the functions shows on the OSD. The u-P will mute the video signal whenever the mode changes. There will be difference SW1/SW2 in difference horizontal frequency, Table 5.1 is the switching table: SW1 SW2 Hf < 40 KHz L L Hf < 58.5 KHz L H Hf > 58.5 KHz H H 20