Daewoo 710B service manual General Servicing Precautions

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SERVICING PRECAUTIONS

SERVICING PRECAUTIONS

CAUTION: Before servicing instruments covered by this service manual, its supplements and addendum, read and follow the SAFETY PRECAUTIONS of this manual.

NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions on page 1 of this manual, always follow the safety precautions.

Remember: Safety First.

General Servicing Precautions

1.Always unplug the AC power cord from the AC power source before:

a.Removing or reinstalling any component, circuit board, module, or any other instrument assembly.

b.Disconnecting or reconnecting any electrical plug or other electrical connection.

c.Connecting a test substitute in parallel with an electrolytic capacitor in the instrument.

CAUTION: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in a explosion hazard.

d. Discharging the picture tube anode.

2.Test high voltage only by measuring it with an appropriate high voltage meter or other voltage measuring device (DVM, FETVOM. etc.) equipped with a suitable high voltage probe. Do not test high voltage by “drawing an arc”.

3.Discharge the picture tube anode only by: (a) first connecting one end of an insulated clip lead to the degaussing or line grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touching the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

4.Do not any spray chemicals on or near this instrument or any or its assemblies.

5.Unless specified otherwise in this service manual, clean electrical contacts by applying the following mixture to the contacts with a pipe cleaner, cotton-tipped stick or comparable nonabrasive applicator: 10% (by volume) Acetone and 90% (by volume) isopropyl alcohol (90%-99% strength).

CAUTION: This is a flammable mixture. Unless specified otherwise in this service manual, lubrication of contacts is not required.

6.Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service manual might be equipped.

7.Do not apply AC power to this instrument and/or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed.

8.Always connect the test instrument ground lead to the appropriate instrument chassis ground before connecting the test instrument positive lead. Always remove the test instrument ground lead last.

9.Use only the test fixtures specified in this service manual with this instrument.

CAUTION: Do not connect the test fixture ground strap to any heatsink in this instrument.

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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
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