Daewoo 710B service manual High Voltage Circuit, Trouble in H.V circuit No Raster

Page 29

10. High Voltage Circuit

10. High Voltage Circuit

Trouble in H.V circuit

(No Raster)

Is

B+(45V) line

voltage normal?

Yes

Is Q574

base waveform

normal?

No

Is Q571

collector waveform

normal?

No

Is Q501

emitter waveform

normal?

No

Is IC501

pin 26 waveform

normal?

No

Is IC501

pin 29 voltage

about 12V?

Yes

Is the

input H.Sync

correct?

No

Trouble in H.Sync

No

Yes

Yes

Yes

Yes

No

Yes

Trouble in power supply circuit

Trouble in Q574 or FBT

Trouble in Q572, Q573 12V Line

Trouble in Q571

Trouble in Q501, Q502

Trouble in power supply

Trouble in IC501 ambient circuit.

27

Image 29

Contents XGA COLOR MONITOR Model 710B Service ManualCONTENTS Safety Check SAFETY PRECAUTIONSFire & Shock Hazard Implosion ProtectionSymbols in the manual GENERAL SAFETY INFORMATIONSymbols as marked on equipment Terms in the manualGeneral Servicing Precautions SERVICING PRECAUTIONSGeneral Soldering Guidelines Electrostatically Sensitive ES DevicesReplacement IC Removal/Replacement“Small-Signal” Discrete Transistor Removal/Replacement RemovalTECHNICAL INFORMATION Power IC, Transistor or Devices Removal/ReplacementDiode Removal/Replacement Abbreviations GENERAL INFORMATIONCaution For Servicing PIN CONNECTORCAUTIONS FOR ADJUSTMENT AND REPAIR ADJUSTMENT KEY OPERATION & ADJUSTMENTRECALL ADJUSTMENT PROCESSCONTRAST BRIGHTNESSOSDOn-Screen Display Menu ROTATION Choose different preset color temperatures or set your own customized Self Diagnosis No Character TROUBLESHOOTING HINTS1. No Character No Raster 2. No RasterOne color is missing 3. A missing ColorAbnormal OSD Font 4. Abnormal OSD FontTrouble in Horizontal output circuit No Raster 5. Horizontal Output CircuitIs H.Sync Unstable pictureinput pin of IC501 correct?Unstable or Abnormal picture 6-2. V.OSC/Deflection CircuitMonitor remains unfocused 7. FocusFocus is poor 7-1. Dynamic FocusPoor convergence 8. ConvergenceAbnormal H.Size 9. Abnormal Picture 9-1. Horizontal Sizechanged, is the H.size changed? 1.Check B+ section of TDA9109 and its ambient circuitAbnormal V.Size 9-2. Vertical SizeTrouble in H.V circuit No Raster 10. High Voltage CircuitSide-Pincusion distortion is excessive or barrel 11. Side-Pincushion CircuitTrouble in P.S.U 12. Power Supply Unit P.S.U8.7V DC? of C104 13V DC?13V DC? Standard Adjustment Conditions ALIGNMENT PROCEDUREPre-Adjustment Main Adjustmentl Repeat e,f,g,h,i,j DIAGRAM Main PCB Component Side PCB LAYOUTMain PCB Solder Side Video PCB Component Side Video PCB Solder Side Page EXPLODED VIEW DIAGRAM Abbreviation of Description REPLACEMENT PARTS LISTImportant Safety Notice PART-CODE CIRCUIT BOARD ELECTRICAL PARTS LISTPART-NAME PART-DESCPART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-NAME PART-DESC PART-CODEPART-NAME PART-DESC PART-CODEPART-NAME PART-DESC Serv ce Manual OVERSEAS SERVICE DEPTPRINTED DATE NOV.1998 DAEWOO ELECTRONICS CO