Daewoo 710B Safety Precautions, Safety Check, Fire & Shock Hazard, Implosion Protection

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SAFETY PRECAUTIONS

SAFETY PRECAUTIONS

CAUTION: No modifications of any circuit should be attempted. Service work should only be performed after you are thoroughly familiar with all of the following safety check and servicing guidelines.

Safety Check

Care should be taken while servicing this analog color display because of the high voltages used in the deflection circuits. These voltages are exposed in such areas as the associated flyback and yoke circuits.

Fire & Shock Hazard

Insert an isolation transformer between the analog color display and AC power line before servicing chassis.

In servicing, pay attention to original lead dress especially in the high voltage circuit. if a short circuit is found, replace all parts which have been overheated as a result of the short circuit.

All the protective devices must be reinstalled per original design.

Soldering must be inspected for possible cold solder points, frayed leads, damaged insulation, solder splashes or sharp solder points. Be certain to remove all foreign materials.

Implosion Protection

Picture tube in this monitor employs integral implosion protection system, but care should be taken to avoid damage and scratching during installation.

Use only same type replacement picture tubes.

IMPORTANT SAFETY NOTICE: There are special components used in analog color display, which are important for safety. These parts are shaded on the schematic diagram and on the replacement parts list. It is essential that these critical parts should be replaced with manufacturer’s specified parts to prevent X-radiation, shock, fire or other hazards. Do not modify the original design without getting a written permission from DAEWOO ELECTRONICS CO. or this will void the original parts and labor warranty.

X-Radiation

WARNING: The only potential source of X-Radiation is the picture tube. However when the high voltage circuitry is operating properly, there is no possibility of an X-Radiation problem. The basic precaution which must be exercised is to keep the high voltage at the following factory recommended level.

NOTE: It is important to use an accurate, periodically calibrated high voltage meter.

To measure the high voltage, use a high-impedance high-voltage meter. Connect(-) to chassis and (+) to the CRT anode button.

Turn the Contrast & brightness control fully counterclockwise.

Measure the high voltage. The high voltage meter should indicate the following factory recommended level.

If the upper meter indication exceeds the maximum level, immediate service is required to prevent the possibility of premature component failure.

To prevent X-Radiation possibility, it is essential to use the specified picture tube.

The normal high voltage is 26.5KV or below, and must not exceed 29KV at zero beam current at rated voltage.

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Contents XGA COLOR MONITOR Model 710B Service ManualCONTENTS Implosion Protection SAFETY PRECAUTIONSSafety Check Fire & Shock HazardTerms in the manual GENERAL SAFETY INFORMATIONSymbols in the manual Symbols as marked on equipmentGeneral Servicing Precautions SERVICING PRECAUTIONSGeneral Soldering Guidelines Electrostatically Sensitive ES DevicesRemoval IC Removal/ReplacementReplacement “Small-Signal” Discrete Transistor Removal/ReplacementPower IC, Transistor or Devices Removal/Replacement Diode Removal/ReplacementTECHNICAL INFORMATION Abbreviations GENERAL INFORMATIONPIN CONNECTOR CAUTIONS FOR ADJUSTMENT AND REPAIRCaution For Servicing ADJUSTMENT KEY OPERATION & ADJUSTMENTBRIGHTNESS ADJUSTMENT PROCESSRECALL CONTRASTOSDOn-Screen Display Menu ROTATION Choose different preset color temperatures or set your own customized Self Diagnosis TROUBLESHOOTING HINTS 1. No CharacterNo 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 Circuitcorrect? Unstable pictureIs H.Sync input pin of IC501Unstable or Abnormal picture 6-2. V.OSC/Deflection CircuitMonitor remains unfocused 7. FocusFocus is poor 7-1. Dynamic FocusPoor convergence 8. Convergence1.Check B+ section of TDA9109 and its ambient circuit 9. Abnormal Picture 9-1. Horizontal SizeAbnormal H.Size changed, is the H.size changed?Abnormal 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.Uof C104 13V DC? 13V DC?8.7V DC? Main Adjustment ALIGNMENT PROCEDUREStandard Adjustment Conditions Pre-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 REPLACEMENT PARTS LIST Important Safety NoticeAbbreviation of Description PART-DESC CIRCUIT BOARD ELECTRICAL PARTS LISTPART-CODE PART-NAMEPART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAME PART-CODE PART-NAMEPART-DESC PART-CODE PART-NAMEPART-DESC PART-CODE DAEWOO ELECTRONICS CO OVERSEAS SERVICE DEPTServ ce Manual PRINTED DATE NOV.1998