Hitachi CM801U Service Manual - Page 25

TROUBLESHOOTING 1. RASTER DOES NOT APPEAR Relevant circuits: Power circuit, Horizontal deflection circuit, High voltage limitter circuit Check supply Voltage AC100-120V/ AC200-240V Abnormal Normal Trouble outside the character monitor Check F901 Abnormal Normal Replace F901 Normal Abnormal 1920, C920, C902, C903, C904, C905 (Change the C97(B) Power Sub 1 Board) In key mode,10 seconds after finishing operation, power LED only light. (Abnormal) No Yes (Normal) The power LED is green. Yes Check + B (More than 50V Less than 180V Normal Horizontal drive pulse Normal Others Abnormal Microprocessor Unit is damaged. Change the Microprocessor Unit. Sync signal input error . Refer to item 2 . Q701, Q702, Q740, Q760, (Change the C97(B) Main Board) Refer to item 2 Check + 8 After removing K981 Others (More than 50V) Less than 180V 0971, D901, 0910, C908, I9A1, 19A2, l9A3,19C1, Q910, Q9A1, Q9A2, Q9C4, Q9C8, D92Z, (Change the C97(B) Main Board) D771 3.- Q741, Q750, Q764, Q800 (Change the C97(B) Main Board -30-