Samsung PS50Q91HX Service Manual

Also see for PS-42C91H: Owner's instructions Owner's instructions

Contents

1. The service instructions are printed on the cabinet, andshould be followed by any service personnel.2. Make sure to unplug the AC power cord from the powersource before starting any repairs.(a) Remove or re-install parts or assemblies.(b) Disconnect the electric plug or connector, if any.(c) Connect the test part in parallel with the electrolyticcapacitor.3. Some parts are placed at a higher position than theprinted board. Insulated tubes or tapes are used for thispurpose. The internal wiring is clamped using buckles toavoid contact with heat emitting parts. These parts areinstalled back to their original position.4. After the repair, make sure to check if the screws, partsor cables are properly installed. Make sure no damage iscaused to the repaired part and its surroundings.5. Check for insulation between the blade of the AC plugand that of any conductive materials (i.e. the metalpanel, input terminal, earphone jack, etc).6. Insulation Check Process: Unplug the power cord fromthe AC source and turn the switch on. Connect the insu-lating resistance meter (500v) to the AC plug blade.The insulating resistance between the blade of the ACplug and that of the conductive material should be morethan 1 ㏁.7. Any B+ interlock should not be damaged.If the metal heat sink is not properly installed, noconnection to the AC power should be made.8. Make sure the grounding lead of the tester is connectedto the chassis ground before connecting to the positivelead. The ground lead of the tester should be removedlast.9. Beware of risks of any current leakage coming intocontact with the high-capacity capacitor.10. The sharp edges of the metal material may causephysical damage, so protect yourself by wearing glovesduring the repair.11. Due to the nature of plasma display panels, partial after-images may appear if a still picture is displayed on thescreen for a long period of time.This is caused by brightness deterioration due to thestorage effect of the panel, and to prevent this fromhappening, we recommend that the brightness and con-trast are reduced.(e.g.) Contrast: 25, Brightness: 50PrecautionSamsung Electronics 1-3Warning 1: First carefully read the "Safety Instruction" in this service manual.When there is a conflict between the service and the safety instructions, follow the safety instruction at all times.Warning 2: Any electrolytic capacitor with the wrong polarity will explode.1-2 Servicing Precautions