Samsung PS42B430P2WXXH Service Manual

1. Make sure all protective devices are properly installedincluding non-metallic handles and compartment coverswhen installing or re-installing the chassis or chassisassemblies.2. Make sure there aren't any gaps between the front andrear cover that anyone could insert they're fingers intoand receive any electrical shock. These gaps includeventilation holes, cracks, etc.Errors may occur when the resistance is below 1.0 ㏁ orover 5.2 ㏁. In these cases, make sure that the deviceis repaired before sending it back to the customer.3. Check for Electricity Leakage (Figure 1-1)Warning: Do not use an insulated transformer forchecking the leakage. Use only those current leakagetesters or mirroring systems that comply with ANSIC101.1 and the Underwriter Laboratory's specifications(UL1410, 59.7).Fig. 1-1 AC Leakage Test4. A high voltage is maintained within the specified limitsusing safety parts, calibration and tolerances. Whenvoltage exceeds the specified limits, check each specialpart.5. Warning for Engineering Changes:Never make any changes or additions to the circuitdesign or the internal part for this product.Ex: Do not add any audio or video accessoryconnectors. This might cause physical damage.Furthermore, any changes or additions to the originaldesign/engineering will invalidate the warranty.6. Warning - Hot Chassis:Some TV chassis are directly connected to one end ofthe AC power cord for electrical reasons. Withoutinsulated transformers, the product can only be repairedsafely when the chassis is connected to the earth end ofthe AC power source.To make sure the AC power cord is properly connected,follow the instructions below. Use the voltmeter tomeasure the voltage between the chassis and the earthground. If the measurement is over 1.0V, unplug the ACpower cord and change the polarity before re-inserting it.Measure the voltage between the chassis and theground again.7. Some TV chassis are shipped with an additionalsecondary grounding system. The secondary system isadjacent to the AC power line. These two groundingsystems are separated in the circuit using anunbreakable/unchangeable insulation material.8. When any parts, material or wiring appear overheated ordamaged, replace them with new immediately. Whenany damage or overheating is detected, correct thisimmediately and make a regular check of possibleerrors.9. Check for the original shape of the lead, especially thatof the antenna wiring, any sharp edges, the AC powerand the high voltage power. Carefully check if the wiringis too tight, incorrectly placed or loose. Never change thespace between the part and the printed circuit board.Check the AC power cord for possible damages.Keep the part or the lead away from any heat-emittingmaterials.10. Safety Indication:Some electrical circuits or device related materialsrequire special attention to their safety features, whichcannot be viewed by the naked eye. If an original part isreplaced with another irregular one, the safety orprotective features will be lost even if the new one has ahigher voltage or more watts.Critical safety parts should be marked with ( ).Use only regular parts for replacements (in particular,flame resistance and dielectric strength specifications).Irregular parts or materials may cause electric shock orfire.PrecautionSamsung Electronics 1-1LEAKAGECURRENTTESTERDEVICEUNDERTESTTEST ALLEXPOSED METALSURFACES2-WIRE CORDALSO TEST WITHPLUG REVERSED(USING AC ADAPTERPLUG AS REQUIRED) EARTHGROUND(READING SHOULDNOT BE ABOVE0.5mA)To avoid possible damage, electric shocks or exposure to radiation, follow the instructions below with regard to safety,installation, service and ESD.1. Precaution1-1 Safety Precautions!