Daewoo DTQ-14N2FC Service Manual

Contents

10GENERAL ADJUSTMENTS1. GENERALIn the majority of cases, all color televisions will need onlyslight touch-up adjustment upon installation. Check thebasic characteristics such as height, focus and sub- basiccharacteristics such as height, focus and sub- bright.Observe the picture for good black and white detailswithout objectionable color shading. If color shading isevident, demagnetize the receiver. If color shading stillpersists, perform purity and convergence adjustments.This should be all that is necessary to achieve Optimumreceiver performance.2. VERTICAL HEIGHT ADJUSTMENT1) Tune in an active channel.2) Adjust brightness and contrast controls for a goodpicture.3) Adjust vertical height control (R305) for approximatelyone half inch over scan at top and bottom of picturescreen.4) Vertical centering adjustment VR316Horizontal centering adjustment VR556.3. FOCUS ADJUSTMENT1) Tune in an active channel.2) Adjust brightness, sharpness and contrast controls for agood picture.3) Adjust focus control (part of T402) for sharp scanninglines and/or sharp picture.4. RF AGC ADJUSTMENT1) Tune in an active channel.2) Using the attenuator, apply the signal of 60dBm to theantenna input terminal.3) Turn RF AGC control (R113) full clockwise until snowor/and noise appears in the picture, then slowly turncontrol counter clockwise until snow or/and noisedisappears.5. HIGH VOLTAGE CHECKHigh voltage is not adjustable but must be checked toverify that the receiver is operating within safe andefficient design limitations as specified:1) Operate Receiver for at least 15 minutes at 120V ACline.2) Set brightness sharpness, contrast and color control tominumum position (Zero beam).3) Connect accurate high voltage meter to CRT anode.The reading should be 24kv~26kvIf a correct reading cannot be obtained, check circuity formalfunctioning components.6. X-RADIATION PROTECTIONCIRCUIT TESTWhen service has been performed on the horizontaldeflection system, high voltage system or B+system, theX-RADIATION protection circuit must be tested for properoperation as follows:1) Operate receiver for at least 15 minutes at 120V ACline.2) Adjust all customer controls for normal picture andsound.3) Short R414(X-RAY Short test), and remove short clip.4) If the operation of horizontal osc. does not stop in stepThe circuit must be repaired, before the set is returnedto the customer.7. CRT GRAY SCALE ADJUSTMENT1) Tune in an active channel.2) Set the COLOR control to minimum.3) Turn the SCREEN control (on T402 fully counter-clockwise.)4) Rotate the RED, GREEN and BLUE BIAS controls(R906, R913, R920) counterclock wise from themaximum, set them to the position where notches inthe knobs become parallel to the surface of P.C.Board.5) Set the GREEN and BLUE DRIVE controls (R911,R918) to the mid position.6) Turn the service switch SW901 (Service Position) onthe CRT board.7) Rotate the SCREEN control (on T402) graduallyclockwise until the second horizontl line following thefirst line appears slightly on the screen. Then turn fullycounterclockwise the two BIAS controls correspondingto the colors of the first and the second horizontallines to eliminated the lines.8) Set the SCREEN control to the position where thethird horizontal line lights slightly on the screen.9) Adjust the two BIAS control set to the minimum in item7) above to obtain the slightly lighted horizontal line inthe same levels of three (red, green, blue) colors. (Theline should be white if the BIAS controls are adjustedproperly.)10) Turn the service switch SW901 again (Normal positionon the CRT board.)11) Press PICTURE-SEL, P-UP and set the brightnessand contrast controls to the maximum.12) Adjust the BLUE and GREEN DRIVE control to obtainproper white-blanced picture in high light areas.13) Using P-SEL, P-DN key, set the brightness andcontrast controls to obtain dark gray raster. Thencheck the white balance in low brightness. Of thewhite balance is not proper, retouch the BIAS controlsand DRIVE controls to obtain a good white balance inboth low and high light areas.8. MAIN B+(103V) ADJUSTMENT1) Tune in an active channel2) Check TP7 (DC 103V Line) using D.V.M3) Adjust voltage control (R820) for main B+(DC 103V)GENERAL ADJUSTMENTS