Samsung D61B Training Manual page 76

Abnormal Screen Image
Replace the 256K and examine the PDP unit
7-2-5 Definitions of Terms
1. Logic Main Board
Applies the PDP video signal by signaling the X, Y Driving Boards and the Logic E, F, G Buffers.
2. 5V, 3.3V
5V : Voltage that is applied to the Logic Buffer by the Logic Main
3.3V : Main voltage that is supplied to the Logic Main Board
7-2-6 Preparations Before the Inspection
1. Test Equipment / Measuring Instruments:
Equipment must retain its precision and comply with regulations.
Inspection Desk: 110V and 220V should be supplied, and there should be enough free space to hold the
Oscilloscope: A 500MHz Frequency Band with 2 or more channels is required.
7-2-7 Switch Descriptions of the Logic Main Board
1) Internal Pattern: Switch Off (Down Position) #2, #4 and Switch On #3 (Up) on SW2001
2) External Pattern: Switch On (Up) #2, #4 and Switch Off #3 (Down) on SW2001
* Switch to the internal pattern for board inspection
* 1 on SW2002 is not used.
!Verify that the output voltages are 5V
and 3.3V when the SMPS is used.
@Set the oscilloscope to 4ms/div and 2V/div.
Connect Probe 1 as illustrated and set it to trigger.
Using Probe 2, analyze the waveforms at each point.
Samsung Electronics
Check the Activity Indicator LED
Check the Internal Pattern
Check the Detailed Waveforms
(Refer to the Inspection Guide)
instruments and test samples.
Check the Video Board
YES
Error of a particular TCP Block
Check the Buffer Board
LOGIC BOARD
M O DEL
OPTION S/W
Inside
42 SD
1 2 3 4
Outside
42 SD
1 2 3 4
Troubleshooting
REMARK
ON
3 ON
O F F
ON
2 , 4
O N
O F F
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