Canon LV-7545U Service Manual

Contents

Canon LV-7545U Service Manual Manual pdf 73 page image

1.2 No pictureThe following items are suspected as possible causes of "no picture". Check the itemsby referring to the block diagrams of the signal processing system on the next page.1) No picture at video input Video inputCheck that the video signal is observed at K10R on the AV unit and pins 3 and 4 ofK8A on the main board.Check that Y and C signals are observed at pin 15 of IC1141.Check that Y and C signals are observed at pins 5 and 7 of IC3101.Check pin 22 of IC101.IN2: Low IN3: High S-video inputCheck that the Y and C signals are observed at pins 47-48 (Y) and 51-52 (C) ofK10R and K8A.Check that the Y and C signals are observed at pins 42 and 44 of IC3101. Component inputCheck that the component signal is observed at pins 7 and 8 (Pb) and pins 11 and12 (Pr) of K10R and K8A.Check that the Y, Pr and Pb signals are observed at test points TP4111PB,TP4111PR and TP4111Y.Check the IN2/IN3 switching signal is observed at pin 22 of IC101.IN2: Low IN3: High All video signal inputCheck that the Y, Cr and Cb signals are observed at test points TP401CR, TP401CBand TP401Y.Check that the Y, Cr and Cb signals are observed at pins 67, 68 and 69 of IC4101.Check that the Y, Pr and Pb signals are observed at pins 73, 74 and 75 of IC4101.Check that the synchronizing signals (AV_HSYNC, AV_VSYNC) are observed at pins4 and 9 of IC3101.Check that the synchronizing signals (AV_HSYNC, AV_VSYNC) are observed at pins65 and 66 of IC4101.Check that the RGB signals are observed at pins 35, 37 and 39 of IC4101.Check that the RGB signals are observed at pins 14, 15 and 4 of IC4181.Check that the RGB signals are observed at pins 8, 10 and 12 of IC201.Check that the synchronizing signals (AV_HSYNC, AV_VSYNC) are observed at pins1 and 3 of IC3231.Check that the CG/HD switching signal is observed at pins 22 of IC201 and pins 9and 10 of IC3231.CG: Low HD: HighPart 4: Troubleshooting4-4