Panasonic TX-37LZ8F User manual

Service Manual
Colour LCD Television
TX-37LZ8F
TX-37LZ8P
GLP23F Chassis
Specifications
Power Source: 220-240V AC, 50Hz
Power Consumption 162W
Stand-by Power Consumption: 0,8W
Aerial Impedance: 75Ωunbalanced, Coaxial Type
Receiving System: PAL-I/H, B/G, D/K,
SECAM B/G, D/K, L/L’
PAL-525/60 (AV only)
M.NTSC (AV only)
NTSC (AV input only)
Receiving Channels: VHF E2-E12 VHF H1-H2 (ITALY)
VHF A-H (ITALY) VHF R1-R2
VHF R3-R5 VHF R6-R12
UHF E21-E69 CATV (S01-S05)
CATV S1-S10 (M1-M10) CATV S11-S20 (U1-U10)
CATV S21-S41 (Hyperband)
Operating Conditions: Temperature: 0°C ÷35°C
Humidity: 20% − 80% RH (non condensing)
Scanning format: 480i(60Hz), 480p(60Hz), 576i(50Hz), 576p(50Hz), 720p(60Hz), 720p(50Hz), 1.080i(60Hz),
1.080i(50Hz), 1.080p(60Hz), 1.080p(50Hz), 1.080p(24Hz)
PC signals: VGA, WVGA, SVGA, XGA, WXGA (compressed)
Horizontal scanning frequency 31 – 69 kHz
Vertical scanning frequency 59 – 86 Hz
ORDER No. PCZ0810189CE
© Panasonic Corporation 2008.
Unauthorized copying and distribu-
tion is a violation of law.

Intermediate Frequency:
Video/Audio
Video 38,9MHz, 33,9MHz
Audio 33,4MHz (B/G), 33,16MHz (A2)
33,05MHz (NICAM B/G, D/K, L)
32,4MHz (D/K), 32,66MHz (CZ STEREO)
40,4MHz (L’), 39,75MHz (L’NICAM)
Colour 34,47MHz (PAL)
34,5MHz, 34,65MHz (SECAM)
38,3MHz, 38,15MHz (SECAM L’)
Terminals:
AV1 IN Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 10kΩ
RGB (21 pin) 0,7V p-p 75Ω
AV1 OUT Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 1kΩ
AV2 IN Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 10kΩ
RGB (21 pin) 0,7V p-p 75Ω
S-video IN (21-pin)Y: 1V p-p 75Ω
C:0,3V p-p 75Ω
AV2 OUT Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 1kΩ
AV3 IN S-Video IN (4-pin) Y: 1V p-p 75Ω
C:0,286V p-p 75Ω
Audio (RCAx2) 500mV rms 10kΩ
Video (RCAx1) 1V p-p 75Ω
HDMI1, HDMI2 Type A Connector
COMPONENT Video (RCAx3) Y:1V p-p 75Ω(including synchronization)
Pb, Pr: ±0,35V p-p 75Ω
AUDIO IN Audio (RCAx2) 500mV rms 10kΩ(for HDMI1, COMPONENT-AUDIO)
AUDIO OUT Audio (RCAx2) 500mV rms 1kΩ(high impedance)
PC HIGH-DENSITY D_SUB 15PIN R,G,B: 700mV p-p 75Ω
HD,VD/TTL Level 2-5V p-p (high impedance)
LCD screen: L5EDD9T00008
1920 x 1080 XGA, 16:9
Visible Diagonal 940mm
Audio Output: 20W (2x10W)
Headphones: 3,5mm, 8ΩImpedance
Accessories supplied : Remote Control 2 x R6 (UM3) Batteries
Dimensions:
Height: Width: Depth:
Including TV stand 645mm 940mm 290mm
TV set only 605mm 940mm 110mm
Mass:
Including TV stand 21.0kg
TV set only 17.5kg
Specifications are subject to change without notice.
Mass and dimensions shown are approximate.
2
This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not
contain warnings or cautions to advise non-technical individuals of potencial dangers in attempting to service a product. Products
powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the
product or products deal within this service information by anyone else could result in serious injury or death.
Warning

CONTENTS
SAFETY PRECAUTIONS........................................... 4
GENERAL GUIDE LINES...................................... 4
TOUCH – CURRENT CHECK............................... 4
PREVENTION OF ELECTROSTATIC DISCHARGE
(ESD) TO ELECTROSTATICALLY SENSITIVE (ES)
DEVICES.................................................................... 5
ABOUT LEAD FREE SOLDER (PBF)......................... 6
SUGGESTED PB FREE SOLDER........................ 6
APPLICABLE SIGNALS.............................................. 7
SERVICE HINTS ........................................................ 8
CHASSIS BOARD LAYOUT....................................... 9
LOCATION OF LEAD WIRING………………………….9
SETTING INSPECTION............................................ 10
SELF-CHECK ........................................................... 11
ADJUSTMENT METHOD.......................................... 12
WIRING DIAGRAM................................................... 13
BLOCK DIAGRAMS.................................................. 14
PARTS LOCATION................................................... 17
REPLACEMENT PARTS LIST.................................. 19
SCHEMATIC DIAGRAMS......................................... 31
A-BOARD (1 OF 5) SCHEMATIC DIAGRAM...... 32
P-BOARD SCHEMATIC DIAGRAM .................... 36
G-BOARD SCHEMATIC DIAGRAM.................... 37
K-BOARD SCHEMATIC DIAGRAM .................... 38
V-BOARD SCHEMATIC DIAGRAM .................... 39
CONDUCTOR VIEWS .............................................. 40
3

Safety Precautions
General Guide Lines
1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated
or damaged by the short circuit.
2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.
3. After servicing, make the following touch current checks to prevent the customer from being exposed to shock hazards.
4. Always ensure panel TKP0E16001 is correctly replaced before returning to customer (see Fig.1).
Touch-Current Check
1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Connect a measuring network for touch currents between each exposed metallic part on the set and a good earth
ground such as a water pipe, as shown in Fig. 2.
3. Use Leakage Current Tester (Simpson 228 or equivalent) to measure the potential across the measuring network.
4. Check each exposed metallic part, and measure the voltage at each point.
5. Reserve the AC plug in the AC outlet and repeat each of the above measure.
6. The potential at any point (TOUCH CURRENT) expressed as voltage U1 and U2, does not exceed the following values:
For a. c.: U1 = 35 V (peak) and U2 = 0.35 V (peak);
For d. c.: U1 = 1.0 V,
Note:
The limit value of U2 = 0.35 V (peak) for a. c. and U1 = 1.0 V for d. c. correspond to the values 0.7 mA (peak) a. c. and
2.0 mA d. c.
The limit value U1 = 35 V (peak) for a. c. correspond to the value 70 mA (peak) a. c. for frequencies greater than 100
kHz.
7. In case a measurement is out of the limits specified, there is a possibility of a shock hazard, and the equipment should
be repaired and rechecked before it is returned to the customer.
Fig. 2
4
TO
APPLIANCES
EXPOSED
METAL PARTS
Resistance values in ohms (Ω)
V
R0=500
Ω
RS=1500
Ω
CS=0.22
μ
F
10k
Ω
0.022
μ
F
COLD
WATER PIPE
(EARTH GROUND)
V: Voltmetr or oscilloscope
(r.m.s. or peak reading)
Measuring network for TOUCH CURRENTS
Input resistance: ≥ 1M
Ω
Input capacitance: ≤ 200pF
Frequency range: 15Hz to 1MHz and d.c.respectively
NOTE – Appropriate measures should be taken to obtain the correct value in case of non-sinusoidal waveforms
U2(V)
Fig. 1

Prevention of Electrostatic Discharge (ESD) to Electrostatically
Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are
called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect
transistors and semiconductor "chip" components. The following techniques should be used to help reduce the incidence of
component damage caused by electrostatic discharge (ESD).
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on
your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD
wrist strap, which should be removed for potential shock reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge build up or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static (ESD
protected)" can generate electrical charge sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil
or comparable conductive material).
7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective
material to the chassis or circuit assembly into which the device will be installed.
Caution
Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the
brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity
(ESD) sufficient to damage an ES device).
There are special components used in this equipment which are important for safety.
These parts are marked by in schematic diagrams, exploded views and replacement parts list. It is essential that
these critical parts should be replaced with manufacturer’s specified parts to prevent shock, fire, or other hazards. Do
not modify the original design without permission of manufacturer.
IMPORTANT SAFETY NOTICE
5

About lead free solder (PbF)
Note: Lead is listed as (Pb) in the periodic table of elements.
In the information below, Pb will refer to Lead solder, and PbF will refer to Lead Free Solder.
The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu).
That is Tin (Sn), Silver (Ag) and Copper (Cu) although other types are available.
This model uses Pb Free solder in it’s manufacture due to environmental conservation issues. For service and repair work,
we’d suggest the use of Pb free solder as well, although Pb solder may be used.
PCBs manufactured using lead free solder will have the PbF within a leaf Symbol
stamped on the back of PCB.
Caution
•Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70 °F (30~40°C)
higher. Please use a high temperature soldering iron and set it to 700 ± 20 °F (370 ± 10 °C).
•Pb free solder will tend to splash when heated too high (about 1100 °F or 600 °C).
If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before
applying Pb solder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.
•After applying PbF solder to double layered boards, please check the component side for excess solder which may
flow onto the opposite side. (see Fig.3)
Suggested Pb free solder
There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder.
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used. (see Fig.4)
Fig.3
Fig.4
6

Applicable signals
Note:
•Signals other than above may not be displayed properly.
•The above signals are reformatted for optimal viewing on your display.
•Applicable input signal for PC is basically compatible to VESA standard timing.
•PC signal is magnified or compressed for display, so that it may not be possible to show fine detail
with sufficient clarity.
Signal name Horizontal frequency (kHz) Vertical frequency (Hz)
640 ×480 @70 Hz 31.47 70.07
640 ×480 @60 Hz 31.47 59.94
640 ×480 @75 Hz 37.50 75.00
800 ×600 @60 Hz 37.88 60.32
800 ×600 @75 Hz 46.88 75.00
800 ×600 @85 Hz 53.67 85.06
852 ×480 @60Hz 31.44 59.89
1,024 ×768 @60Hz 48.36 60.00
1,024 ×768 @70Hz 56.48 70.07
1,024 ×768 @75Hz 60.02 75.03
1,024 ×768 @85Hz 68.68 85.00
1,280 ×1024 @60Hz 63.98 60.02
1,366 ×768 @60Hz 48.39 60.04
Macintosh13” (640 ×480) 35.00 66.67
Macintosh16” (832 ×624) 49.73 74.55
Macintosh21” (1,152 ×870) 68.68 75.06
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Signal name COMPONENT HDMI
525 (480) / 60i * *
525 (480) / 60p * *
625 (576) / 50i * *
625 (576) / 50p * *
750 (720) / 60p * *
750 (720) / 50p * *
1,125 (1,080) / 60i * *
1,125 (1,080) / 50i * *
1,125 (1,080) / 60p *
1,125 (1,080) / 50p *
1,125 (1,080) / 24p *
Component (Y, Pb, Pr), HDMI
PC (D-sub 15P)

Service Hints
How to remove the backcover
Remove the 14 fixing screws. (see Fig.5)
How to remove the Pedestal assembly
Lay the main unit face down. (see Fig.6)
Remove the 4 fixing screws and the pedestal assembly. (see Fig.7)
Fig.6
8
SCREWS SCREWS
Fig.5
Fig.7
SCREWS

Chassis Board Layout
Location of Lead Wiring
To find the Part Number of required wire in Replacement Parts List click on the wire name in red box.
Board Name Function
A-Board AV Terminal, Audio Video Processor, Speaker out, TV tuner,
HDMI, HDMI Receiver
G-Board Side AV Terminal
V-Board Remote Receiver, R&G LED, C.A.T.S.
K-Board Main Switch
P-Board Main Input, Power Supply, Power Supply Regulator
9
G-BOARD
A-BOARD P-BOARD
V-BOARD K-BOARD
A18
G51-A7
A5-SP
A8-V1
K1
P2
G51
TU101A
INVERTER
V1
P5
A5 P1
A1
A18-Panel_LVDS
A16
A7 A8
A4
A10
A16/P5-INVERTER
A4-K1

Setting Inspection
Voltage Confirmation
Confirm the following voltages:
A board
Description Test point Range
STBY1V TP1838 1,015-1,05V
STBY3,3V TP1840 3,14-3,47V
MAIN1V TP3832 1,0-1,05V
MAIN3,3V TP3833 3,13-3,47V
CORE1V TP1842 1,06-1,1V
MAIN2,5V TP1845 2,83-2,63V
MAIN1,8V TP1846 1,728-1,9V
MAIN1,25V TP1844 1,245-1,275V
MAIN5V TP3826 4,775-5,25V
STBY5V TP3813 4,9-5,4V
MAIN8V TP3823 7,6-8,4V
PANEL12V TP3824 11,97-12,81V
CEC3,8V TP3814 3,5-4,2V
TUNER30V TP3801 28-32V
TERMINATION TP3831 0,794-1,02
P board
Description Test point Normal condition Stand By
AUDIO VCC TP865 13,6V+/- 0,8V 0V
STB 5V6 TP853 5.65+/- 0,25V 5.65+/- 0,25V
24V IN TP856 24V+/- 1,5V 0V
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