Switch Mode Power Supply Troubleshooting - LG 42PQ30 Training Manual

SWITCH MODE POWER SUPPLY Troubleshooting

SWITCH MODE POWER SUPPLY Troubleshooting
This Section of the Presentation will cover troubleshooting the Switch Mode Power Supply for
the Single Scan Plasma. Upon completion of the section the technician will have a
better understanding of the operation of the Power Supply Circuit and will be able to
locate voltage and test points needed for troubleshooting and alignments.
• DC Voltages developed on the SMPS
• Adjustments VA and VS.
• Always refer to the Voltage Sticker located on the back of the panel, in the upper Left
Hand side for the correct voltage levels for the VA, VS, -VY, Vscan, and Z Bias as these
voltages will vary from Panel to Panel even in the same size category.
• Set-Up and Ve are just for Label location identification and are not adjusted in this panel.
SMPS P/N EAY58349601
Check the silk screen label on the top center of the Board of the Power Supply itself to identify the Board
P/N.
We will examine the Operation of this Power Supply.
31 Preliminary Information 42PQ30