1-1
1. Precautions
1. Precautions
1-1. Safety Precautions
Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as
electrical shock.
1-1-1. Warnings
For continued safety, do not attempt to modify the circuit board.
Disconnect the AC power and DC power jack before servicing.
1-1-2. Servicing the LCD TV
When servicing the LCD TV, Disconnect the AC line cord from the AC outlet.
It is essential that service technicians have an accurate voltage meter available at all times.
Check the calibration of this meter periodically.
1-1-3. Fire and Shock Hazard
Before returning the LCD TV to the user, perform the following safety checks:
Inspect each lead dress to make certain that the leads are not pinched or that hardware is not lodged between the
chassis and other metal parts in the LCD TV.
Inspect all protective devices such as nonmetallic control knobs, insulating materials, cabinet backs, adjustment and
compartment covers or shields, isolation resistorcapacitor networks, mechanical insulators, etc.
Leakage Current Hot Check (Figure 1-1):
WARNING
: Do not use an isolation transformer during this test.
Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI
C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410, 59.7).
With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. With the unit’s AC switch
first in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit,
etc.) and all exposed metal parts, including: metal cabinets, screwheads and control shafts.
The current measured should not exceed 0.5 milliamp.
Reverse the power-plug prongs in the AC outlet and repeat the test.
1-1-4. Product Safety Notices
Some electrical and mechanical parts have special safetyrelated characteristics which are often not evident from visual
inspection. The protection they give may not be obtained by replacing them with components rated for higher voltage,
wattage, etc. Parts that have special safety characteristics are identified by
on schematics and parts lists. A substitute
replacement that does not have the same safety characteristics as the recommended replacement part might create
shock, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever
appropriate.
1.
2.
1.
2.
1.
2.
3.
4.
DEVICE
UNDER
TEST
(READING SHOULD)
NOT BE ABOVE 0.5mA
LEAKAGE
CURRENT
TESTER
TEST ALL
EXPOSED METAL
SURFACES
2-WIRE CORD
*ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
EARTH
GROUND
Figure 1-1. Leakage Current Test Circuit
Summary of Contents for LE26B450C4H
Page 4: ...4 Signal Flows Information ...
Page 5: ...4 Signal Flows Information ...
Page 6: ...4 Signal Flows Information ...
Page 7: ...4 Signal Flows Information ...
Page 8: ...4 Signal Flows Information ...
Page 9: ...4 Signal Flows Information ...
Page 13: ...4 Signal Flows Information DDR SIGNALS go into SEMS12 directly ...
Page 14: ...4 Signal Flows Information CI SIGNALS go into SEMS12 directly ...
Page 15: ...4 Signal Flows Information LVDS SIGNALS go into TCON BD directly ...
Page 50: ...1 4 1 Precautions Memo ...
Page 64: ...4 5 4 Troubleshooting LVDS PC_RGB HV_Sync MAINBOARD BOTTOM ...
Page 65: ...4 6 4 Troubleshooting WAVEFORMS 1 PC input V sink H sink R G B 2 LVDS output ...
Page 67: ...4 8 4 Troubleshooting HDMI 2 HDMI 1 MAINBOARD TOP ...
Page 68: ...4 9 4 Troubleshooting WAVEFORMS 3 HDMI input RX_Data RX_Clk 2 LVDS output ...
Page 70: ...4 11 4 Troubleshooting B3 3V_PW Tuner_CVBS B5V_VCCT_PW MAINBOARD TOP ...
Page 71: ...4 12 4 Troubleshooting WAVEFORMS 4 CVBS OUT Grey Bar 2 LVDS output ...
Page 73: ...4 14 4 Troubleshooting TS_DATA B1 2V_PW B3 3V_PW B5V_VCCT_PW MAINBOARD TOP ...
Page 74: ...4 15 4 Troubleshooting WAVEFORMS 2 LVDS output ...
Page 76: ...4 17 4 Troubleshooting MAINBOARD BOTTOM ...
Page 77: ...4 18 4 Troubleshooting WAVEFORMS 4 CVBS OUT Grey Bar 2 LVDS output ...
Page 79: ...4 20 4 Troubleshooting MAINBOARD BOTTOM ...
Page 80: ...4 21 4 Troubleshooting WAVEFORMS 5 Compnent_Y Gray scale Pb Pr Color bar 2 LVDS output ...
Page 83: ...4 24 4 Troubleshooting WAVEFORMS 6 I2C Data 7 Speaker out ...
Page 101: ...4 42 4 Troubleshooting 4 8 PCB diagram ...
Page 102: ...4 43 4 Troubleshooting ...
Page 103: ...6 1 6 Wiring Diagram 6 Wiring Diagram 6 1 Wiring Diagram 26 32 37 ...