Daewoo 710B service manual Troubleshooting Hints, No Character

Page 17
TROUBLESHOOTING HINTS

TROUBLESHOOTING HINTS

1. No Character

No Character

Are the

 

 

 

 

 

 

 

 

No

Contrast &

 

 

 

 

 

 

 

 

Brightness Controls

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

maximum

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is whole

 

 

 

 

 

 

 

 

No

screen bright?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is CRT

 

 

 

 

 

 

 

Yes

Cathode (Rk, Gk, Bk)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

signal level

 

Rk, Gk, Bk

normal?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

About 45Vpp

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is the

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

output signal of the

 

 

 

 

 

 

 

Yes

(pin 21, 24, 26) pre-amp

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(IC801, KA2500)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

normal?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Change the Contrast & Brightness control to maximum

No Raster

Refer to

No Raster

 

Check the peripheral circuit of CRT Board

Check the video output circuit and IC803 (pin 1, 3, 5) and their ambient circuit

Is 12V DC line

 

No

normal?

 

 

 

Yes

 

 

 

 

 

 

 

 

 

Is clamping

 

No

pulse (pin 18 of IC801)

 

 

 

 

normal?

 

 

 

Yes

 

 

 

 

 

 

 

 

No

Is input signal

 

normal?

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

Trouble in IC801 and

 

 

its ambient circuit

 

 

 

 

 

 

Trouble in 12V DC line of the Main PWB

Check the clamping pulse circuit

Check the signal cable

15

Image 17
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