Adjustments; Adjustment Procedure - Panasonic TX-25AD1D Service Manual

Adjustment Procedure

Adjustment
Operating voltage
Focus
RF AGC
Comb Filter Adjustment
The remote control is used for entering and storing adjustments, with the exception of cut-off adjustments which must always be done prior to
service adjustment. Perform adjustments in accordance with screen display. The display on the screen also specifies the CCU variants as
well as the approx. setting values. The adjustment sequence for the service mode is indicated below.
1. Set the Bass to maximum position, set the Treble to minimum
position, press the F button followed by the volume down
button on the customer controls at the front of the TV and at
the same time press the Reveal button on the remote control,
this will place the TV into the Service Mode.
2. Press the RED / GREEN buttons to step up / down through
the functions.
NOTE: This TV also has the option of using a Memory Pack which enables you to copy the preset TV channels into the Memory Pack and
then download them onto this or any other EURO-2S TV set.
TV to Memory Pack process
1. Plug the memory pack into the lower of the two 21 pin
terminals at the back of the TV and switch the TV on. If the
TV has only one 21 pin connector then this will be able to
accept the memory pack.
2. Go into the Service Mode as explained above. The screen
will show:-
3. Press the blue button on the remote control. The screen will
show:-
4. Press the STORE button on the TV. The screen will
5. All the tuning information stored inside the TV will now be
transferred to the Memory Pack. This process will take 2-3
minutes to complete and when finished the screen will show:-
Memory Pack to TV Process
Errors
If an error occurs while using the Memory Pack the TV will detect this and the screen will show:-
If this happens then press the Normalisation button and repeat the process that was being used. If the errors continue to occur then check the
connectors between the TV and the memory pack and check the 9V battery inside the memory pack.
Signal
Test pattern
Test pattern
Standard colour bar
signal
PAL colour bar pattern
Conditions
230 V - beam current 0
Place an oscilloscope on
tuner AGC
Oscilloscope
3. Press the YELLOW / BLUE buttons to alter the function
values.
4. Press the STORE button after each adjustment has been
made to store the required values.
5. To exit the Service Mode press the Normalisation button..
1. Plug the memory pack into the lower of the two 21 pin
terminals at the back of the TV and switch the TV on. If the
TV has only one 21 pin connector then this will be able to
accept the memory pack.
2. Go into the Service Mode as explained above. The screen
will show:-
3. Press the STORE button on the TV. The screen will
4. All the tuning information stored inside the Memory Pack will
now be transferred to the TV. This process will take 2-3
show:- minutes to complete and when finished the screen will show:-
5. The tuning information from the Memory Pack has now been
copied into the TV
6. To exit from the Service Mode press the Normalisation
button.
7. The process has now been completed and the Memory Pack
can now be removed.

Adjustments

Adjust P633
Focus at line
transformer
Adjust P4701 clockwise
Adjust P2601
Settings/Special
features
Measure Cathode D651
so a Voltmeter shows
+147V"0.5
Optimum setting
Slowly turn P4701 anti-
clockwise, set P4701
where the RF AGC
voltage drops by 0.2V
from maximum.
Confirm input video
signal (pin 4 W2601 is
1Vp-p). Adjust P2601 to
obtain 2Vp-p at TPF1.
show:-