Overview; Introduction; Basic Troubleshooting Steps; Caution - LG 42PG20 Training Manual

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INTRODUCTION

This manual covers two models from the 2008 Plasma Display Panel (PDP) product line.
Each model is an HDTV with integrated HD tuner. All 2008 PDP models include USB Media
Host and SimpLink. USB Media Host consists of a USB port on the back of the TV that
supports USB flash memory drives loaded with media or firmware for the TV. SimpLink
allows for control of other LG SimpLink products via the HDMI connection.
All PDP TV models are covered by a one year parts and labor warranty. Refer to the last
page of the owner's manual for more warranty information. When making a warranty repair
involving a service bulletin, be sure to refer to the service bulletin number in the warratny
claim.

BASIC TROUBLeSHOOTING STePS

Define - Look at the symptom carefully and determine what circuits could be causing the
failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts and
check for possible overheated components. Capacitors will sometimes leak dielectric
material and give off a distinct odor. The frequency of power supplies will change with
the load, or listen for a relay closing, etc. Observation of the front Power LED may
give some clues.
Localize - Carefully check the symptom and determining the circuits to be checked. After
giving a thorough examination using your senses, check the DC Supply Voltages to
those circuits under test. Always confirm the supplies are not only the proper level,
but are noise free. If the supplies are missing check the resistance for possible short
circuits.
Isolate - To further isolate the failure, check for the proper waveforms with an Oscilloscope
to make a final determination of the failure. Look for correct Amplitude Phasing and
Timing of the signals. Also check for the proper Duty Cycle of the signals. Sometimes
"glitches" or "road bumps" will be an indication of an imminent failure.
Correct - The final step is to correct the problem. Be careful of static sensitive components
and make sure to check the DC Supplies for proper levels. Make all necessary
adjustments. Lastly, always perform a Safety AC Leakage Test before returning the
product back to the Customer.

CAUTION

1) A (approximately) 10 minute pre-run time is required before any adjustments are
performed.
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2008 PDP
5
PDP Training - Fall 2008