Hitachi CRP-450 TV field amplitude is compressed into narrow band, the upper part of the scan line sparse, the dark on the bottom, no scanning line fault repair method -Service Manual Download|Circuit Download|Download Drawings|schematic download|route map download|free download user manual

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Hitachi CRP-450 TV field amplitude is compressed into narrow band, the upper part of the scan line sparse, the dark on the bottom, no scanning line fault repair method

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Field linear bad the cause of the problem are: to promote to the field of the output stage through linear correction network failure; Promote and field output working point offset, nonlinear etc. K8Fservice manual download site
K8Fservice manual download site
(1) measurement field scanning piece of dc voltage IC701 (1) ~ (4) feet K8Fservice manual download site
(2) check field output OTL midpoint M601 end feet to IC701 R613 negative feedback branch element. (3) feet between integral C605, R612, no exception. K8Fservice manual download site
(3) check field deflection coil to R7611 IC701 (4) feet between current negative feedback branch component, R610, R624, R608 is no exception. K8Fservice manual download site
(4) check the OTL field output point to the negative feedback branch R609 IC701 4 feet, found that has been open. K8Fservice manual download site
R609 open to negative feedback linear correction branch off, make a picture in the first half was secondary, and OTL to middle IC701 end feet dc working point to improve, make the pipe under the field output saturation conduction, so that the grating compressed into a level in the second half.K8Fservice manual download site