Panasonic TX-21RX20T Service Manual ▷ View online
1.6. GP41Z Chassis Block Diagram
ONLY FOR MODEL WITH
5TH HARMONIC COIL
CRT
defl.
coil
CRT
DRIVE
L
MAIN
POWER
SWITCH
SW
PVP
IC1801
R/G/B
SCL SDA
CVBS IN
REAR INPUTS
AV1 : V/L/R AV3 : YUV/V/L/R
VCT-IF
IC601
V_IN
CVBS OUT
MON_OUT
R G B
R/G/B
MON_OUT
V/L/R
EEPROM
IC1101
SCL SDA
A_IN
IF
H
A
AUDIO OUT
V
SPEAKER
AUDIO
AMP
IC2301
V OUT
TUNER
PP
GEOMAGNETIC
GEO
SIDE INPUTS
AV2 : V/L/R
G
PANEL KEY
K
REMOTE RECEIVER
& LED
V
LINE FILTER
P
PIP MODEL
H OUT
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TX-21RX20T
2 Service Hints
2.1. Service Position for E-Board
1. Remove the back cover.
2. Stand the TV set as shown in Fig. 2.
3. Remove the A-Board from the TV set by pulling the main board out as shown in Fig. 2.
2. Stand the TV set as shown in Fig. 2.
3. Remove the A-Board from the TV set by pulling the main board out as shown in Fig. 2.
Fig. 2
2.2. Service Mode Explanation
1. Service Mode Access
a) Set the timer ON.
b) Press remote’s RECALL (
b) Press remote’s RECALL (
) and panel’s volume down key simultaneously to enter SERVICE 1.
2. Service Mode 1 Controls
Key 3/4
Previous/Next Service 1 Item
Key 8/9
Adjust user Brightness (-/+)
Program up/down
Program position up/down
Volume +
Increment of selected item
Volume -
Decrement of selected item
OK
Store/Save selected item
Normalize
Exit service mode
3. Service Mode 2 Controls
To enter SERVICE 2; press channel key ‘1’ in SERVICE 1 entry screen.
Key 3/4
Previous/Next Service 2 Item
Key 8/9
Toggle for option bit 0-7
Program up/down
Program position up/down
Volume +
Increment of selected item
Volume -
Decrement of selected item
OK
Store/Save selected item
Normalize
Exit service mode
NOTE:- Service Mode 2 options bit refer to each model front cover spec.
4. Service Mode 3 Controls
To enter SERVICE 3; press channel key ‘1’ in SERVICE 2 entry screen.
Key 3/4
Previous/Next Service 1 Item
Program up/down
Program position up/down
Volume +
Increment of selected item
Volume -
Decrement of selected item
OK
Store/Save selected item
Normalize
Exit service mode
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TX-21RX20T
2.3. Adjustment for White Balance
Preparation:
1. Receive the white balance pattern and aging should be performed over 30 minutes.
2. Set the picture menu to DYNAMIC NORMAL.
3. Degausse the CRT face.
4. Fix the CRT colour analyzer receiver unit to CRT face.
1. Receive the white balance pattern and aging should be performed over 30 minutes.
2. Set the picture menu to DYNAMIC NORMAL.
3. Degausse the CRT face.
4. Fix the CRT colour analyzer receiver unit to CRT face.
Adjustment of Low Light
1. Adjustment Sub Bright, so that Y = 6.5 ± 1.0 nit.
2. Adjustment R-CUT OFF, so that X = 0.241 ± 0.005 nit.
3. Adjustment G-CUT OFF, so that Y = 0.242 ± 0.005 nit.
1. Adjustment Sub Bright, so that Y = 6.5 ± 1.0 nit.
2. Adjustment R-CUT OFF, so that X = 0.241 ± 0.005 nit.
3. Adjustment G-CUT OFF, so that Y = 0.242 ± 0.005 nit.
Adjustment of High Light
1. Adjustment Sub Bright, so that Y = 150 nit.
2. Adjustment R-Drive, so that X = 0.263 ± 0.003 nit.
3. Adjustment B-Drive, so that Y = 0.261 ± 0.003 nit.
1. Adjustment Sub Bright, so that Y = 150 nit.
2. Adjustment R-Drive, so that X = 0.263 ± 0.003 nit.
3. Adjustment B-Drive, so that Y = 0.261 ± 0.003 nit.
2.4. Adjustment for CRT CUT OFF
Preparation:
1. Connect the oscilloscope probe to TPL5.
2. Screen VR min.
3. Set the data Sub Bright, Bright.
4. In service Mode at “Bright” dac press [5] in factory mode to enter vertical line and adjust by volume down or up button.
5. Adjust “Screen VR” until 1-H Line appears.
1. Connect the oscilloscope probe to TPL5.
2. Screen VR min.
3. Set the data Sub Bright, Bright.
4. In service Mode at “Bright” dac press [5] in factory mode to enter vertical line and adjust by volume down or up button.
5. Adjust “Screen VR” until 1-H Line appears.
2.5. Adjustment Procedure
2.5.1. +B Voltage
Item / preparation
1. Operate the TV set.
2. Set control as follows :
1. Operate the TV set.
2. Set control as follows :
Brightness ........... minimum
Contrast ............... minimum
Contrast ............... minimum
Adjustment procedure
1. Confirm the DC voltage at the indicated test points, as follows :
1. Confirm the DC voltage at the indicated test points, as follows :
TPA 15 : 3.35 ± 0.2 V
TPA 16 : 130 ± 2 V
TPA 17 : 8.25 ± 0.35 V
TPA 18 : 1.85 ± 0.15 V
TPA 19 : 5.30 ± 0.2 V
TPA 20 : 188 ± 15 V
TPA 16 : 130 ± 2 V
TPA 17 : 8.25 ± 0.35 V
TPA 18 : 1.85 ± 0.15 V
TPA 19 : 5.30 ± 0.2 V
TPA 20 : 188 ± 15 V
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TX-21RX20T
2.5.2. High Voltage
Item / preparation
1. Receive the crosshatch pattern.
2. Set to 0 Beam.
1. Receive the crosshatch pattern.
2. Set to 0 Beam.
Screen VR .......... minimum
Contrast .............. minimum
Contrast .............. minimum
Adjustment procedure
1. Connect a DC voltage meter to TPA 16 and confirm the +B voltage is 130.0 V ± 2.
2. Connect a high frequency voltmeter to heater and confirm that voltage reads 6.3 V (RMS) ± 0.24.
3. Normalize the brightness and contrast.
1. Connect a DC voltage meter to TPA 16 and confirm the +B voltage is 130.0 V ± 2.
2. Connect a high frequency voltmeter to heater and confirm that voltage reads 6.3 V (RMS) ± 0.24.
3. Normalize the brightness and contrast.
2.6. Adjustment of Purity
1. INSTRUMENTS
a. Purity Jig
b. Helmhortz device
b. Helmhortz device
2. PREPARATION
a. Set the Helmhortz device to local magnetic field.
Horizontal : 0 ± 0.03 × 10-4T
b. Aging should be performed over 60 minutes.
c. Receive the purity pattern (White pattern).
d. Picture menu : CONTRAST ... Max. BRIGHT ... Max.
e. Set V-CENTER to [4].
f.
c. Receive the purity pattern (White pattern).
d. Picture menu : CONTRAST ... Max. BRIGHT ... Max.
e. Set V-CENTER to [4].
f.
Static convergence should have been roughly adjusted.
g. Connect DC current meter through FBT (pin 3) and adjust to [1200 ± 10%] µA.
3. ADJUSTMENT
a. Set both purity magnets’ knobs to top.
b. Adjust the purity so that the markers on monitor scope of purity jig become symmetrical in horizontal direction.
c. Only for stripe CRT, correct vertical centre by purity magnet too.
d. Set up deflection yoke so that the position of deflection yoke becomes [10 µm ± 5] forward on monitor scope at this time by
b. Adjust the purity so that the markers on monitor scope of purity jig become symmetrical in horizontal direction.
c. Only for stripe CRT, correct vertical centre by purity magnet too.
d. Set up deflection yoke so that the position of deflection yoke becomes [10 µm ± 5] forward on monitor scope at this time by
attention note to tile deflection yoke.
e. Repeat procedures (a) ~ (d).
f.
f.
Tighten deflection yoke band.
g. Adjust beam landing by microscope. (Only for model change or check instruments)
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TX-21RX20T
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