Training Manual

1 Training ManualCourse: CRT-01 CRTT roubleshootingDiagnostics and TroubleshootingRecommended Troubleshooting & Repairing Guide: LED & LCD TV Repair Tips ebook More information on T-con Board & Mainboard Secret Repair Tips! LCD TV Repair Tips & Case Histories Collection of LCD TV Repair Tips Vol-3 LCD/LED Monitor Repair Case Histories by Jestine Yong LCD/LED & 3D TV Repair Membership Site Plasma & 3D TV Repair Membership Site Projection TV & DLP/LCD Projector Repair Membership Site Troubleshooting & Repairing LCD TV Guide Plasma TV Repair Guide- Display Fault Troubleshooting Basic LCD TV Repair Secrets Revealed LCD Monitor Repair Guide Vol .1- 10 Trus Repair Case Histories of LCD Monitor SMPS-Switch Mode Power Supply Repair Guide Testing Electronic Components like a Pro- For Beginner Please visit: Table of Contents1.

2 Inside the Repair Analysis CRT Related (black, white, burn, dust); color mixing;shadows; line - popping noise fro the CRT gun; rasternoise; intermittent focus; intermittentbrightness picture; sound is present; heater filamentsare color in convergence; color screen is out of with retrace lines (normal or lowbrightness), no or no picture; sound is present, limitedbrightness level contamination or incorrect colors, typicallyat the picture, no sound, HV will not turn DEAD Unit Troubleshooting (DEADor PIXX)..7 CRT No Picture or Dark PictureTroubleshooting (NPIX or PIXS)..9 Poor Emission, , Hot Arcing, No Color, IntermittentPicture, Jiter, Raster Only or RetraceLines (ARCS, PIXC, PIXI, PICJ,PIXL)..11 PIXL, PIXI, PIXK PICC OR ARCS - Damage Caused by Convergence / Beam LandingTroubleshooting (PIXD, PIXW).. Convergence / Beam CRT Convergence Geometric Distortion(PIXD, PIXW).. Geometric Focus Troubleshooting (PIXF).

3 CRT Convergence Axis Axis AX-1 Chasis PCB Interconnections and Functional DescriptionsChapter 1 - Inside the CRTFIGURE 1-1 - EXPLODED VIEWSOCKET BASEAPERTURE GRILLELECTRON GUNPHOSPHOR &CARBON STRIPES12/5 1-2 - TOP VIEW OF ELECTRON Repair Analysis FlowchartChapter 2 - Repair Analysis FlowchartRepair damagedpart of this point,check for for visibledamaged partsor looseconnectionsOK= Set returned to CustomerYesNoNGNGAge unitFIGURE 2-1 - ANALYSIS FLOWCHART12/3 sent to tocheck the reportedfaultCheck forphysicaldamageIt is likely to havecaused theproblemTest TVRepair usingservice bulletinAge set &monitorYesNoNGOKNoYesOKNoCheck forservicebulletinsAge unitNoRepair DamageYesGo to next pageTurn set ON toobserve fault ortest Repair Analysis FlowchartFIGURE 2-2 - ANALYSIS FLOW (CONTINUED)12/3 voltagesBoard connectionsFuses*Refer to informationsheetDEADNo PictureNo Sound(PIXX)EIA CodeNo PictureDark Raster(NPIX, PIXS)EIA CodeWill set turn on?

4 Step 1Is bright Rastervisible?Step 2 CHECKH eatersBoard voltagesBoard connections*Refer to informationsheetNoCHECKB oard voltagesBoard connectionsGround connections*Refer to informationsheetPicture Condition: Noisy Intermittently turns off Black & white only No videoStep 3 Raster onlyIntermittent pictureJitter - JumpingNo colorArcingEIA CodeYesYesCHECKF ocusLandingConvergenceGeometry*Refer to informationsheetCHECKS pots, scatchesColor spotsShadows, lines, etc.*Refer to informationsheetIs picture qualitypoor?Step 4 YesNoIs there a flaw onoutside surface ofinside of the screen?Step 5 CRT blemish,Physicaldamage(APPR)(DAMG)EIA CodePicture distortedPicture noisyOut of focusPoor colorWrong color(PIXD) (PIXF)(PIXW)EIA CodeNo43. CRT Related SymptomsChapter 3 - CRT Related SymptomsSpots (black, white, burn, dust); color mixing; shadows; line kinksCause:Flaw on or behind phosphor affecting the overall appearance of the Code: APPREIA Description: Appearance defectCTV Description: Visual defectArcing - popping noise from the CRT gun; raster noise; intermittent focus;intermittent brightness changesCause:Current leak, stray electrons.

5 Particles in the electron gun cause intermittent current leakage Code: ARCS; PIXI; PIXJEIA Description: Arcing; Intermittent picture; Jittery/unstable pictureCTV Description: Arcing; ShortNo picture; sound is present, heater filaments are ONCause:Cathode emission; short; low vacuum. The cathode emission may be weak; grids may be shorted; may beintermittent or Code: NPIXEIA Description: No pictureCTV Description: White balance, shortNo color in pictureCause:CRT short at cathode or grids causing a defect in B board (video drive).EIA Code: PIXCEIA Description: No color in pictureCTV Description: Short53. CRT Related SymptomsPoor convergence; color distortionCause:CRT gun is not perpendicular to the CRT face - physical damage; internal IBR resistor is damaged. Colordistortion may consist of colored shadows in the Code: PIXDEIA Description: Picture distorted/noisyCTV Description: ConvergenceGeometric distortionCause:CRT gun is not perpendicular to the CRT face - physical damage; internal IBR resistor is Code: PIXDEIA Description: Picture distorted/noisyCTV Description: GeometricEntire screen is out of focusCause:Leak current between G-3 and G-4.

6 This may be constant or Code: PIXFEIA Description: Picture out of focusCTV Description: FocusRaster with retrace lines (normal or low brightness), no videoCause:Short between grids (typically G1 and G2). G2 drive circuit may become Code: PIXLEIA Description: Raster is present, but no pictureCTV Description: ShortDark or no picture, sound is present, limited brightness level adjustmentCause:Poor emission due to shorted grids or vacuum leak. Sound is present, but the picture is weak or cannot Code: PIXSEIA Description: Dark pictureCTV Description: White balance63. CRT Related SymptomsColor contamination or incorrect colors, typically at the :Purity beam landing; DY ring magnets; CRT magnets; degauss defectiveEIA Code: PIXWEIA Description: Poor or incorrect colorCTV Description: LandingSymptom/Cause: Mislanding, purity shiftNo picture, no sound. HV will not turn :Vacuum leak; broken neck; frit leak; open filament heaters. Main fuse may be Code: PIXX, DEADEIA Description: No picture, no soundCTV Description: Broken CRT, open heaters74.

7 DEAD Unit Troubleshooting (DEAD or PIXX)Chapter 4 - DEAD Unit Troubleshooting (DEAD or PIXX)CRT CausesNo HeatersTurn the power ON and visually check the 4-1 FIGURE 4-2 Broken CRTLook for damage to the neck of body of the 4-3 - BROKEN CRT84. DEAD Unit Troubleshooting (DEAD or PIXX)Table 4-1 DEAD Unit (DEAD, PIXX) Possible causes other than the CRT Symptom CHECK ITEMS COUNTER MEASURE Power cord plugged in / Power on ? Plug in / Turn power on Fuse Change fuse Anode cap position Connect anode cap securely if off Check G2 level If too high (2 flash OCP), lower H-out may be defective. If too low (5 flash AKB) will occur. Adjust for correct level. Check B+ voltage Check for short circuit to GND. AE-5A may be low H-out (2 flash OCP). Power IC problem. The fuse may be broken replace fuse. Check FBT soldering connection Re-solder bad connection. Check for crack board near FBT Replace board Check M board connection Secure M board, insert correctly.

8 Check service bulletin information Implement fix as per bulletin. No Picture / No Power Check DY connection Check if DY connector is inserted into the board correctly. 95. No Picture or Dark Picture Troubleshooting (NPIX or PIXS)Chapter 5 - No Picture or Dark PictureTroubleshooting (NPIX or PIXS)Poor Emission, VacuumAdjust the Cathode drive and G-2 level and check for brightness , Hot ShortWith CRT socket off, check each CRT pin for a short with another pin. (Note: G-1 and heaters have multiplepins.)Heat expansion may cause hot shorts . For hot shorts, turn the set on, wait until problem occurs, then quicklyshut down and check for HeatersTurn the power ON and visually check the filament heaters for glowFIGURE 5-1 HEATER NOGOODFIGURE 5-212/5 OK105. No Picture or Dark Picture Troubleshooting (NPIX or PIXS)Table 5-1 No Picture or Dark Picture (NPIX or PIXS) Possible causes other than the CRT Symptom CHECK ITEMS COUNTER MEASURE No Picture Voltages to each electron gun.

9 Trace back to power source for the cause. Video drive circuit. Replace IC. Check if anode cap is on. Connect the anode cap securely. C board: may be loose or off. (Normally a 5 flash AKB error) Attach the C board properly. Filament heater. Heater voltage should be about Vrms (Sound should work). Trace cause of missing heater voltage and repair. G2 voltage. (2 flash OCP or 5 flash AKB error) If too high, lower H-out may be broken (2 flash OCP error). If too low, 5 flash AKB error will occur. Readjust. B+ voltage Repair short circuit to GND. AE-5A may be low H-out (2 flash OCP). Power IC problem. Broken / blown fuse. Repair FBT mounting Repair / re-solder bad connection. FBT circuit - cracked board Replace board. M board connection Secure M board, insert properly. DY connector insertion Reconnect DY properly Check service bulletin information Implement fix as per bulletin. 116. Arcing, No Color, Intermittent Picture, Jitter, Raster Only or Retrace LinesChapter 6 - Arcing, No Color, Intermittent Picture,Jitter, Raster Only or Retrace Lines(ARCS, PIXC, PIXI, PIXJ, PIXL)PIXL, PIXI, PIXJ, PICC or ARCS CRT CausesFour causes may produce above symptoms and all are related to current flow between electron gun Arcing (Popping sound)Cause:Current discharge from a high voltage potential to ground or to low voltage can occur when foreign particles as small as 2mm are present in the CRT gun.

10 Factors for arcing are:voltage potential differences between the electrodes; distances between the electrodes; shape, size andlocation of the between Electrode ~2mmDust, burr ~2mm in height(+)(-)Neck GlassFIGURE 6-112/5 dustPin-shaped dustHighLow12/5 6-2 Occasionally, arcing occurs between the cathodes, causing emission ElectronsCause:As a result of cold emissions, electrons flow froma lower electric potential of the gun to a higherpotential of the gun in areas that they would nototherwise normally Emission occurs when an electron flow isinduced by a strong electric field between twoparallel : VdElectric Field : FFIGURE 6-3126. Arcing, No Color, Intermittent Picture, Jitter, Raster Only or Retrace LeaksCause:These leaks occur between the CRT pins on the CRT socket and are caused by external contamination onthe socket between the pins or by insufficient :Clean socket and apply RTV compound in areas :A complete short between two grids.