This Service manual is issued as a servic e guide for the models of the NA8ML family li sted above. Includ ed in this
manual are a set of schematic, block diagrams, functional descriptions, alignment procedures, disassembly
procedures and a complete parts list.
“WARNING! This Service Man ual is desig ned for expe rienced repa ir technici ans only and is not designed f or use by t he general p ublic.
It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired onl y by experienced pro fessional technicians. Any attempt to
service or repair the product or products dealt with in this Service Manual by anyone else could result in serious injury or death.”
The service technician is required to read and follow the “Safety Precautions” and “Important Safety Notice” in this Main Manual.
Copyright 2001 by M atsush ita Elec tric Co rporatio n of
America. All rights reserved. Unauthorized copying
®
and distribution is a violation of law.
Chassis Service Adjustment Procedures
All service adjustments are factory preset and should not require adjustment unless controls and/or
associated components are replaced.
Note: Connect the (-) lead of the voltmeter to the appropriate ground. Use heat sink when the HOT ground symbol
( ) is used. Otherwise, use COLD ground () — Tuner shield.
A-BOARD
IC2301
IC001
T
U
N
E
R
T
U
N
E
R
L008
Q002
IC002
+
C3023
-
TP
IC881
IC101
IC1801
IC3001
A/V REAR INPUTS
18
IC882
IC883
D-BOARD
Q804
D751
L826
L824
+
C840
D827
D825
T801
Q801
Q551
D511
MOMENTARILY CONNECT A JUMPER FOR ENTERING SERVICE MODE (TP8 to COLD GND)
140.0V B+ Voltage Confirmation
1. Set the Bright and the Picture to Minimum by
using the Picture Menu.
2. Connect the DVM between
ground ().
3. Confirm that B+ voltage is 140.0V ± 1.5V. This
(+ side) and cold
TPP17
LOCAT ION (D-Board)VOLTAGE
TPD7
(by D511)
220V220.0V ± 9.0V
LOCAT ION (A-Board)VOLTAGE
TP A 6
(by IC883)
MAIN 12V12.0V ± 0.5V
voltage supplies B+ to the Horizontal Output &
Flyback circuits.
Source Voltage Chart
120V AC line input. Se t the Bright and the Picture to
Minimum by using th e Picture Menu. Use cold ground
) for the (-) lead of the DVM.
(
TP A 7
TPA8
TPA16
TP A 18
(by IC3001)
(by L008)
(by Q002)
(by C3023)
MAIN 9V9.0V ± 0.5V
MAIN 5V5.0V ± 0.3V
STBY 3.3V3.3V ± 0.2V
BTL 30V32.0V ± 2.0V
.
LOCATION (D-Board)VOLTAGE
TPP17
TPP25
TPP19
(by D825)
(by D827)
(by Q804)
+B2140.0V ± 1.5V
9V9.0V ± 1.5V
15V15.0V ± 2.0V
Adjust Picture Menu for normalized video adjustments.
High Voltage Check
1. Select an active TV channel and confirm that
horizontal is in sync.
2. Adjust Brightness and Picture using Picture Icon
menu so video just disappears.
TPP20
TPP21
(by C840)
(by L826)
15V (VER.)15.0V ± 1.5V
-15V (VER.)-15.0V ± 1.5V
3. Confirm B+ 140.0V is within limit.
4. Using a high voltage meter confirm that the High
Voltage is 31.0kV ± 1.0kV.
TPP22(
by L824
) SOUND32.5V ± 2.0V
- 12 -
Serviceman Mode (Electronic Controls)
This Receiver has electronic technology using the I²C Bus Concept. It performs as a control function and it
replaces many mechanical controls. Instead of adjusting mechanical controls individually, many of the control
functions are now performed by using “On Screen Display Menu”. (The Serviceman Adjustment Mode.)
Note: It is suggested that the tec hnician reads all the way through and understand the following proc edure for
Entering/Exiting th e Serviceman Adjustment Mode; then proce ed with the instructi ons working with th e
Receiver. When becoming f ami li ar with t he procedure, the Fl ow Chart for Servicema n Mod e may be used
as a quick guide.
Quick Entry to Serviceman Mode:
At times when minor adjustments need to be done to the electronic controls, the method of Entering the
serviceman Mode without removal of the cabinet back is as follows using the Remote Control:
1. Select SET-UP icon and select CABLE mode.
2. Select TIMER icon and set SLEEP time for 30 Min.
3. Press ACTION button 3 times to exit menus.
4. Tune to the Channel 124.
5. Adjust VOLUME to minimum ( 0) .
6. Press the VOL button (decrease) on Receiver. Red “CHK” appears in upper corner.
To toggle between Aging and Serviceman modes:
While the “CHK” is displayed on the left top corner of the CRT, pressing the Action and the Volume Up buttons
on the Receiver simultaneously will toggle between the modes. Red “CHK” for Serviceman and yellow “CHK” for
Aging.
7. Press the Power Bu tton on the Remote Control to select one of the Serviceman Adjustment Modes.
1) B= Serviceman VCJ SUB-DATA ADJUSTEMENT.
2) C= Serviceman VCJ CUT-OFF ADJU STMENT.
3) D= Serviceman GEOMETRY ADJUSTMENT.
4) M= Serviceman MTS ADJ U S TM EN TS .
5) P= Service man PIP ADJUSTMENT.
6) S= Serviceman S OPTION ADJUSTMENTS.
7) X = Serviceman X OPTION ADJ U S TM ENT.
8) E = Serviceman E OPTION ADJ U S TM ENTS
9) “CHK” = Normal operation of CHANNEL and VOLUME .
Note: Only the appli c able settings for
b
32 B 02 215 C 0
a
b
a
the Receiver serviced will be
available (See
a
in Fig. 20).
An address Menu appears in the right
hand corner of the screen
Figure 20. Serviceman Mode Menu Adjustments.
Exiting the Serviceman Mode:
Press the Action and the Power buttons on the Receiver simultaneously for at least 2 seconds.
THE RECEIVER EXITS SERVICEMAN MODE.
The Receiver momentarily shuts off; then comes back on tuned to channel 3 with a preset level of sound.
Any programmed channels, channels caption data and some others user defined settings will be erased.
IMPORTANT NOTE:
Always Exit the Serviceman Mode
Following Adjustments.
- 17 -
Press the Power Button on the Remote Control to select the Serviceman Adjustment .
For Adjustments:
1.Press Channel Up/Down on the
Remote Control to select one of
the available Se rvice Adjustments
(a in Fig. 20).
Note: Write Down the original
value set (b in
Fig. 20
) for
each address before
modifying anything. It is
easy to erroneously adjust
the wrong item.
2.Press Volume Up/Down on theRemote Control to adjust the
level of the selected Service
Adjustment (b in Fig. 20).