Sanyo DS19310 Service Manual
REFERENCE No. SM5110224
DS19310, G8EDM, PRODUCT CODE 111355483
AS
FILE NO.
SERVICE MANUAL Remote Control Color
Television
DS19310 (U.S.A.)
(CANADA)
ORIGINAL VERSION
Chassis No. 19310-00
NOTE: Match the Chassis No. on
the unit’s back cover with
the Chassis No. in the
Service Manual.
If the Original Version
Service Manual Chassis
No. does not match the
unit’s, additional Service
Literature is required. You
must refer to “Notices” to the
Original Service Manual
prior to servicing the unit.
Contents
Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . 2
Service Adjustments. . . . . . . . . . . . . . . . . . . 3 - 8
Service Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Purity and Convergence Adjustments . . . 10 - 11
Mechanical Disassemblies . . . . . . . . . . . . . . . 12
Chassis Electrical Parts List . . . . . . . . . . . 13 - 20
Cabinet Parts List . . . . . . . . . . . . . . . . . . . . . . 21
Component and Test Point Locations. . . . 22 - 24
Schematic Diagrams . . . . . . . . . . . . . . . . 25 - 32
Block Diagram . . . . . . . . . . . . . . . . . . . . . 26 - 27
Voltage Charts . . . . . . . . . . . . . . . . . . . . . 26 - 27
Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Specifications
Power Rating . . . . . . . . . . . . . . . . . . . . . . 120V, 60Hz
68W (Avg), 1.4A (Max)
Antenna Input Impedance . . . . . . . . . . . . . . . . . . 75Ω
UHF/VHF/CATV
Receiving Channel. . . . . . . . . . . . . . . . . 2 - 13 (VHF),
14 - 69 (UHF),
01, 14-94, 95-125 (CATV)
Remote Ready. . . . . . . . . . . . 24 Key Remote Control
Sound Output . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 W
Intermediate Frequency
Picture IF Carrier . . . . . . . . . . . . . . . . . . 45.75MHz
Sound IF Carrier. . . . . . . . . . . . . . . . . . . 41.25MHz
Color Sub Carrier . . . . . . . . . . . . . . . . . . 42.17MHz
Picture Tube. . . . . . . . . . . . A48AAB37X/A48AGD12X
Semiconductors
Integrated Circuits. . . . . . . . . . . . . . . . . . . . . . . . . 7
Transistors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Except within Tuner and RC Pre-Amp.
Cabinet Dimensions
Width. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488mm
Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452mm
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467mm
— 2 —
SAFETY PRECAUTIONS
WARNING: The chassis of this receiver has a floating ground
with the potential of one half the AC line voltage in respect to
earth ground. Service should not be attempted by anyone not
familiar with the precautions necessary when working on this
type of equipment.
The following precautions must be observed:
1. An isolation transformer must be connected in the power line
between the receiver and the AC line before any service is
performed on the receiver.
2. Comply with all caution and safety-related notes provided on
the side of the cabinet, inside the cabinet, on the chassis, and
the picture tube.
3. When replacing a chassis in the cabinet, always be certain
that all the protective devices are installed properly, such as
control knobs, adjustment covers, shields and barriers.
DO NOT OPERATE THIS TELEVISION RECEIVER
WITHOUT THE PROTECTIVE SHIELD IN POSITION AND
PROPERLY SECURED.
4. Before replacing the back cover of the set, thoroughly inspect
the inside of the cabinet to see that no stray parts or tools
have been left inside.
Before returning any television to the customer, the
service technician must perform the following safety checks to
be sure that the unit is completely safe to operate without
danger of electrical shock.
ANTENNA COLD CHECK
Remove AC plug from the 120 VAC outlet and place a jumper
across the two blades. Connect one lead of an ohmmeter to the
jumpered AC plug, and touch the other lead to each exposed
antenna terminal (UHF and VHF antenna terminals). The resistance must measure between 1M ohm and 5.2M ohm. Any
resistance value below or above this range indicates an abnormality which requires corrective action.
LEAKAGE CURRENT CHECK
Plug the AC line cord directly into a 120 VAC outlet. (Do not use
an isolation transformer for this check.) Use an AC voltmeter,
that has 5000 ohms per volt or more sensitivity. Connect a 1500
ohm 10 watt resistor, paralleled by a 0.15 µF 150 VAC capacitor,
between a known good earth ground (water pipe, conduit, etc.)
and all exposed metal parts of the cabinet (antennas, handle
bracket, metal cabinet, screw heads, metal overlays, control
shafts, etc.). Measure the AC voltage across the 1500 ohm
resistor. The AC voltage should not exceed 750 mV. A reading
exceeding 750 mV indicates that a dangerous potential exists.
The fault must be located and corrected. Repeat the above test
with the receiver power plug reversed.
NEVER RETURN A RECEIVER TO THE CUSTOMER
WITHOUT TAKING THE NECESSARY CORRECTIVE ACTION.
X-RADIATION PRECAUTION
The primary source of X-RADIATION in solid-state receivers is the
picture tube. The picture tube is specially constructed to limit X-Ray
emission. For continued X-RADIATION protection, the replacement
tube must be the same type as the original (including the suffix letter in the part numbers). Excessive high voltage may produce
potentially hazardous X-RADIATION. To avoid such hazards, the
high voltage must be maintained within specific limits. Refer to the XRADIATION WARNING NOTE on the CHASSIS SCHEMATIC in
this service manual for specific high voltage limits.If the high voltage
exceeds specified limits, check the components specified on the
chassis schematic diagram and take the necessary corrective
action. Carefully follow the instructions for the +B Voltage Check
and the High Voltage Check to maintain the high voltage within the
specified limits.
HIGH VOLTAGE HOLD-DOWN TEST
To prevent X-RADIATION from the picture tube due to excessive
high voltage, a HOLD-DOWN circuit is provided in the high voltage circuit. Every time the receiver is serviced, the high voltage
HOLD-DOWN circuit must be tested for proper operation. Refer
to the HIGH VOLTAGE HOLD-DOWN TEST in service adjustments.
PRODUCT SAFETY NOTICE
When replacing components in a receiver, always keep in mind
the necessary product safety precautions. Pay special attention
to the replacement of components marked with a star (★) in the
parts list and in the schematic diagrams. To ensure safe product
operation, it is necessary to replace those components with the
exact same PARTS.
SAFETY INSTRUCTIONS
0.15 µF 150V AC
1500 ohm
10 watt
Good earth ground
such as a water pipe,
conduit, etc.
AC OUTLET
TELEVISION
RECEIVER
READING SHOULD NOT EXCEED 750 mV.
AC VOLTMETER
(5000 ohms per volt or more sensitivity)
To be touched to all of exposed metal parts.
Voltmeter Hook-up for Leakage Current Check.
GENERAL
This set has an On-screen Service Menu system included in the CPU that allows remote operation for most of the service adjustments.
ON-SCREEN SERVICE MENU SYSTEM
1. Enter the Service Menu:
• While pressing the MENU key, reconnect the AC power cord. The Service Menu Display will now appear. (See Figure 1 below.)
2. Service Adjustments:
• Press the ▲ or ▼ key to select the desired service menu you want to adjust. (See page 4 for On-screen Service Menu.)
• Use the + or – key to adjust the data.
3. Exit from the Service Menu:
• Press the MENU key to turn off the Service Menu display.
SERVICE ADJUSTMENTS
— 3 —
IC802 (EEPROM) REPLACEMENT
When IC802 (EEPROM) is replaced, IC801 (CPU) will automatically write the initial reference data into IC802 for basic TV operation.
However, the bus data should be checked and some bus data should be set up before attempting the service adjustments.
(See pages 4 – 5 for detailed information.)
INITIAL BUS DATA SETUP
Note: When IC802 (EEPROM) is replaced, the Service Menu No. 001 HP (H Phase), No. 013 TDS (Trap & D SW), No. 014 AF
(Auto Flesh), No. 024 AG (AFC Gain), No. 026 SCO (Sub-Color), No. 027 STI (Sub-Tint), and No. 031 HR (OSD Display H-Position)
should be set up for proper TV operation before attempting the service adjustments.
1. Disconnect the AC power cord (AC 120V line).
2. While pressing the MENU key, reconnect the AC power cord. The Service Menu display will now appear.
3. Select No. 001 HP (H Phase) with ▲ or ▼ key. Adjust the data with + or – key for 14.
4. Select No. 013 TDS (Trap & D SW) with ▲ or ▼ key. Adjust the data with + or – key for 1.
5. Select No. 014 AF (Auto Flesh) with ▲ or ▼ key. Adjust the data with + or – key for 1.
6. Select No. 024 AG (AFC Gain), with ▲ or ▼ key. Adjust the data with + or – key for 0.
7. Select No. 026 SCO (Sub Color) with ▲ or ▼ key. Adjust the data with + or – key for 7.
8. Select No. 027 STI (Sub Tint) with ▲ or ▼ key. Adjust the data with + or – key for 18.
9. Select No. 031 HR (OSD Display H-Position) with ▲ or ▼ key. Adjust the data with + or – key for 28.
10. Press the MENU key to turn off the Service Menu display.
No. Data
XXX XXX XXX XXXXXXXX
DECIMALDATA
(ZERO SUPPRESSED)
Figure 1. Service Menu Display
No. 001-040, 043-115
TITLE
BINARYDATA
(8 bit)
No. Data
XXX DRV XXX XXXXXXXX
No. 041
TITLE
BINARYDATA
(8 bit)
OR
DECIMALDATA
(ZERO SUPPRESSED)
— 4 —
Table 1. ON-SCREEN SERVICE MENU
When IC802 (EEPROM) is replaced, check the bus data to confirm they are the same as below. The shaded menu should be checked
and be set up or readjusted according to the procedures described in the following pages. Initial Setup Data marked with an * should
be changed from Initial Reference Data. (See page 3 for Initial Bus Data Setup.)
No. TITLE
INITIAL REFERENCE INITIAL SETUP
RANGE OF DATA FUNCTION
DATA DATA
001 HP 15 14* 0~31 Horizontal Phase (Horizontal Centering)
002 IAS 0 0 0, 1 IF AGC Switch 0: TV (Normal) 1: AV (IF Gain Minimum)
003 RAD 25 25 0~63 RF AGC Delay
004 PT 64 64 0~127 PLL Tuning
005 ADA 31 31 0~63 APC Detect Adjust
006 CD 0 0 0, 1 C-Diff
007 VS 32 32 0~63 Vertical Size
008 RB 0 0 0~255 Red Bias
009 GB 0 0 0~255 Green Bias
010 BB 0 0 0~255 Blue Bias
011 RD 60 60 0~127 Red Drive
012 BD 60 60 0~127 Blue Drive
013 TDS 0 1* 0, 1 Trap & D (B.P.F.) Switch
0: OFF 1: ON
014 AF 0 1* 0, 1 Auto Flesh 0: OFF 1: ON
015 BS 0 0 0, 1 Black Stretch 1: OFF 0: ON
016 VL 4 4 0~7 Video Level
017 FL 15 15 0~31 FM Level
018 NIS 1 1 0, 1 N/I Switch (Black Noise Inverter) 1: OFF 0: ON
019 ABL 1 1 0,1 ABL Defeat 0: OFF 1: ON
020 WP 1 1 0,1 White Peak Limiter
1: OFF 0: ON
021 GD 7 7 0~15 Green Drive Reduction
022 VC 0 0 0~7 Vert. Comp
023 VD 32 32 0~63 Vert. DC
024 AG 3 0* 0~3 AFC Gain 00: Auto 01: High Gain 10: Low Gain 11: Non-Gate
025 SB 32 32 0~63 Sub-Brightness
026 SCO 10 7* 0~31 Sub-Color
027 STI 14 18* 0~31 Sub-Tint
028 SSH 8 8 0~15 Sub-Sharpness
029 OPT 0 0 0~255 Option 1 (See Note 1 page 5.)
030 OP2 0 0 0~255 Option 2 (See Note 2 page 5.)
031 HR 24 28* 0~63 H-Position (OSD H-Position)
032 INP N/A N/A N/A N/A
033 STE N/A N/A N/A N/A
034 FIL N/A N/A N/A N/A
035 LSP N/A N/A N/A N/A
036 HSP N/A N/A N/A N/A
037 SPV N/A N/A N/A N/A
038 PCO N/A N/A N/A N/A
039 PTI N/A N/A N/A N/A
040 SBO 0 0 0~255 Sub Bright Offset
041 DRV
0~127 Red drive Adjustment (See Note 3 page 5.)
0~127 Blue Drive Adjustment (See Note 3 page 5.)
– 0 0 0~255 Red Bias Adjustment (See Note 4 page 5.)
042 – 0 0 0~255 Green Bias Adjustment (See Note 4 page 5.)
– 0 0 0~255 Blue Bias Adjustment (See Note 4 page 5.)
043 T00 0 0 0~255 N/A
↓↓ ↓ ↓ ↓ ↓
115 T48 0 0 0~255 N/A
SERVICE ADJUSTMENTS (Continued)
— 5 —
PROGRAM CODES
The microprocessor used in this model is a multi-purpose type
and is used in several different models. To ensure proper
operation and the correct features for your particular model, the
Program Codes must be correct.
Note 1. Option Data 1 (No. 029 OPT) should be decimal 0
(00000000 binary). See page 3 INITIAL DATA SETUP, step 9,
for set up procedure. If this program code is wrong the TV will
not operate properly.
Note 2. Option Data 2 (NO. 030 OP2) should be decimal 0
(00000000 binary). If this program code is wrong the TV will not
operate properly.
Note 3. Red/Blue Drive Adjustments in Service Menu No.
041 DRV: Adjust Red and Blue Drive Levels alternately with 1,
3, 7, and 9 keys on the remote control. (See figure 2.) The Drive
Level adjustment data will be written in the Service Menu No.
011 and 012 automatically.
1
2
3
4 5 6
7 98
RB(–)
RB(+)
BB(–)
BB(+)
(N/A)
GB(–)
(N/A)
GB(+)
(N/A)
FOR RED BIAS ADJUSTMENT
FOR BLUE BIAS ADJUSTMENT
FOR GREEN BIAS ADJUSTMENT
Figure 2.
Figure 3.
1
2
3
4 5 6
7 98
RD(–)
RD(+)
BD(–)
BD(+)
(N/A)
(N/A)
(N/A)
(N/A)
(N/A)
FOR RED DRIVE ADJUSTMENT
FOR BLUE DRIVE ADJUSTMENT
BIT FUNCTION
DATA
01
0 TV/HOTEL TV HOTEL
1 NOT USED N/A
2 NOT USED N/A
3 NOT USED N/A
4 NOT USED N/A
5 NOT USED N/A
6 NOT USED N/A
7 NOT USED N/A
Note 4. Red/Green/Blue Bias Adjustments in Service Menu
No. 042: Adjust each Bias Level with 1, 3, 4, 6, 7, or 9 key on
the remote control. (See figure 3.) The Bias Level adjustment
data will be written in the Service Menu No. 008 ~ 010
automatically.
BIT FUNCTION
DATA
01
0 AV INPUT MONO STEREO
1 NOT USED N/A
2 NOT USED N/A
3 NOT USED N/A
4 NOT USED N/A
5 NOT USED N/A
6 NOT USED N/A
7 TV FRONT KEY MENU GAME
SERVICE ADJUSTMENTS (Continued)
— 6 —
ANTENNA CONNECTIONS
This receiver is designed for UHF/VHF reception. A 75 ohm
terminal is provided for UHF and VHF receptions. When
connecting a CATV antenna system, connect the 75 ohm
coaxial cable directly to the 75 ohm terminal. For 300 ohm VHF
antenna, use an adapter (not included with the TV set).
CIRCUIT PROTECTION
Fuse F601 (4A) is included in the AC line. This fuse must be
replaced with the proper fuse (see Parts List).
+B VOLTAGE CHECK
Connect Voltmeter + lead to TJ1 135V and – lead to ground
(TE7). Connect receiver to AC 120V line. Tune receiver to an
active channel. Set the picture controls to the Auto levels.
Voltage must measure between +133.0V and 136.1V. If the
voltage is out of this range, the power circuit must be checked.
No +B adjustment is provided on this chassis.
HORIZONTAL CENTERING ADJUSTMENT
1. Tune receiver to an active channel.
2. Check that picture is in the horizontal center of TV screen.
If picture is not centered horizontally, perform steps 3 ~ 6.
3. Turn off the receiver and disconnect the AC power cord
(120V AC line).
4. While pressing the MENU key, reconnect the AC power cord.
The Service Menu display will now appear.
5. Select No. 001 HP (Horizontal Phase) with ▲ or ▼ key.
6. Adjust the data with + or – key for proper horizontal center.
To turn off the Service Menu display, press the MENU key.
VERTICAL SIZE ADJUSTMENT
1. Tune receiver to an active channel.
2. Check the vertical size of the picture. If the vertical size is too
large or small, perform steps 3 ~ 6.
3. Turn off the receiver and disconnect the AC power cord
(120V AC line).
4. While pressing the MENU key, reconnect the AC power cord.
The Service Menu display will now appear.
5. Select No. 007 VS (Vertical Size) with ▲ or ▼ key.
6. Adjust the data with + or –key for full scan. To turn off the
Service Menu display, press the MENU key.
VERTICAL CENTERING ADJUSTMENT
1. Tune receiver to an active channel.
2. Check that picture is in the vertical center of TV screen. If picture
center is too low, replace resistor R513 (3.9K ohm, 1/6W) with
470 ohm, 1W resistor. If picture center is too high, connect
resistor R512 (470 ohm, 1W).
GRAYSCALE ADJUSTMENT
1. Set the picture controls to the Auto levels.
2. Turn off the receiver and disconnect the AC power cord
(120V AC line).
3. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
4. Select No. 008 RB (Red Bias), No. 009 GB (Green Bias),
and No. 010 BB (Blue Bias) with ▲ or ▼ key and set each
data to 0 with + or – key.
5. Select No. 011 RD (Red Drive) and No. 012 BD (Blue Drive)
with ▲ or ▼ key and set each data to 60 with + or – key.
6. Set No. 021 GD (G Drive Reduction) data to 7, No. 025 SB
(Sub-Brightness) data to 32, No. 026 SCO (Sub-Color) data
to 7, No. 027 STI (Sub-Tint) to 18 and No. 028 SSH (SubSharpness) data to 8 with ▲ or ▼, and + or – keys.
7. Turn Screen Control (T402) to minimum (fully counterclockwise).
8. Select the Service Menu No. 042 (Bias Adjustments) with ▲
or ▼ key.
9. Advance Screen Control (T402) clockwise to obtain just
visible one color line. If line does not appear, place this
control to maximum (fully clockwise).
10. Raise each Bias Level with 3, 6, and 9 keys to obtain just
visible white line. (See Figure 4 below.)
11. Select the Service Menu No. 041 DRV (Drive Adjustments) with
▲ or ▼ key.
12. Adjust Red and Blue Drive Levels alternately with 1, 3, 7, or
9 key to produce normal black and white picture in highlight
areas. (See figure 5 below.)
13. Check for proper grayscale at all brightness levels.
To turn off the Service Menu display, press the MENU key.
Note: If Grayscale Adjustment is made after picture tube
replacement, check Brightness Level Adjustment.
FOCUS ADJUSTMENT
Adjust focus control (T402) for well defined scanning lines.
1
2
3
4 5 6
7 98
RB(–)
RB(+)
BB(–)
BB(+)
(N/A)
GB(–)
(N/A)
GB(+)
(N/A)
FOR RED BIAS ADJUSTMENT
FOR BLUE BIAS ADJUSTMENT
FOR GREEN BIAS ADJUSTMENT
Figure 4. Remote Control Number keys’ function in Service
Menu No. 042
1
2
3
4 5 6
7 98
RD(–)
RD(+)
BD(–)
BD(+)
(N/A)
(N/A)
(N/A)
(N/A)
(N/A)
Figure 5. Remote Control Number keys’function in
Service Menu No. 041 DRV
FOR RED DRIVE ADJUSTMENT
FOR BLUE DRIVE ADJUSTMENT
CAUTION
FOR CONTINUED PROTECTION AGAINST ARISK
OF FIRE, REPLACE ONLY WITH THE SAME TYPE
4A, 125V FUSE.
ATTENTION : POUR MAINTENIR LA PROTECTION
CONTRE LES RISQUES D’ INCENDIE UTILISER UN
FUSIBLE DE RECHANGE DE MEME TYPE 4A, 125V
.
4A 125V
— 7 —
APC DET ADJUSTMENT
Note: APC DET must be adjusted after IC101 (Signal
Processor), IC802 (EEPROM) or T151 (PLL VCO Coil)
is replaced.
1. Disconnect the antenna terminal and the AC power cord
(120V AC line).
2. Connect voltmeter + lead to TP113 on main board and
– lead to main board ground.
3. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
4. Select No. 002 IAS (IF AGC Switch) with ▲ or ▼ key. and
adjust the data to 1 with + or – key.
5. Select No. 005 ADA (APC Det. Adjust.) with ▲ or ▼ key. and
adjust the data with + or – key for 3.8 ± 1.0 VDC. Voltage
change in the ADA BUS data adjustments is shown in
Figure 6.
6. Disconnect voltmeter from chassis.
PLL TUNING ADJUSTMENT
Note: APC DET Adjustment must be completed before
attempting PLL Tuning Adjustment.
1. Disconnect the antenna terminal and the AC power cord
(120V AC line).
2. Connect voltmeter + lead to TP113 on main board and
– lead to main board ground.
3. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
4. Select No. 002 IAS (IF AGC Switch) with ▲ or ▼ key.and
adjust the data to 0 with + or – key.
5. Select No. 004 PT (PLL Tuning) with ▲ or ▼ key.
6. Connect the antenna terminal and select a good quality
active color channel in your area, using keys 0 ~ 9 on the
remote control transmitter.
7. Adjust the data with + or – key for 3.8 ± 1.0 VDC. Voltage
change in the PT BUS data adjustments is shown in Figure
7.
8. Disconnect voltmeter from chassis.
Select every active channel with 0 ~ 9 keys and the scanning
keys, and check to be sure the AFT is operating properly.
VIDEO LEVEL ADJUSTMENT
1. Connect a color-bar generator to the antenna terminal.
2. Switch the generator to a white field (100 IRE).
3. Connect oscilloscope + lead to terminal TP16A on main
board and – lead to main board ground.
4. Set the picture controls to the Auto levels.
5. Confirm voltage reading of 2.0 ± 0.2 Vp-p. If voltage is
within this range, Skip to Step 10. If voltage is out of this
range, go to step 6.
6. Turn off the receiver and disconnect the AC power cord
(120V AC line).
7. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
8. Select No. 016 VL (Video Level) with ▲ or ▼ key.
9. Adjust the data with + or –key for 2.0 ± 0.2 Vp-p. To turn off
the Service Menu display, press the MENU key.
10. Disconnect voltmeter from chassis.
RF-AGC ADJUSTMENT
1. Tune receiver to strongest VHF station in your area.
2. Set contrast and brightness controls for maximum.
3. Turn off the receiver and disconnect the AC power cord
(120V AC line).
4. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
5. Select No. 003 RAD (RF-AGC Delay) with ▲ or ▼ key.
6. Adjust the data with + or – key in the direction which
causes snow to appear; then in the opposite direction until
the snow just disappears.
7 . To turn off the Service Menu display, press the MENU key.
BRIGHTNESS LEVEL ADJUSTMENT
Note: Grayscale, RF-AGC, Video Level and High Voltage Check
must be adjusted before attempting Brightness Level
Adjustment.
1. Connect a color-bar generator to the antenna terminals.
2. Switch the generator to the crosshatch pattern.
3. Set the picture controls to the Auto levels.
4. Connect voltmeter (high impedance) + lead to terminal
TP51 and – lead to terminal TP50 on main board. Set
voltmeter for 1.5V ~ 3V range.
5. Turn off the receiver and disconnect the AC power cord
(120V AC line).
6. While pressing the MENU key, reconnect the AC power
cord. The Service Menu display will now appear.
7. Select No. 025 SB (Sub Brightness) with ▲ or ▼ key.
8. Adjust the data with + or – key for 820mVDC.
9. Press the MENU key to turn off the Service Menu display.
10. Check brightness level on every active channel, readjust
(repeat steps 5 ~ 9) if necessary.
Note: Do not set to excessive brightness level, otherwise the
contrast level will be suppressed.
63 (steps)
ADA BUS DATA
VO LTAGE
TP113
3.8V
Figure 6. Voltage Change in ADA BUS data Adjustments
Figure 7. Voltage Change in PT BUS data Adjustments
127 (steps)
PT BUS DATA
VO LTAGE
TP113
3.8V
HIGH VOLTAGE CHECK
Note: +B (+135V) Voltage Check and Grayscale Adjustment
must be completed before attempting High Voltage Check.
1. Connect high voltage voltmeter negative lead to ground, and
connect + lead to anode of picture tube.
2. Tune receiver to an active channel and confirm TV is
operating properly.
3. Eliminate the beam current by adjusting the contrast and
brightness controls to minimum.
4. Confirm high voltage is within 25.0 KV and 27.0 KV. If reading
is not within range, check horizontal circuit.
No high-voltage adjustment is provided on this chassis.
HIGH VOLTAGE HOLD-DOWN TEST
Every time the receiver is serviced, the HIGH VOLTAGE
HOLD-DOWN circuit must be tested for proper operation by
following these steps:
1. Connect receiver to 120V AC line. Tune receiver to active
channel. Set the picture controls to the Auto levels.
2. Check that the voltage measured between TP7 and TE7
(ground side) is within 16.5 VDC to 21 VDC. If the voltage is
out of this range, the Hold-Down Circuit must be checked.
3. Connect a DC Voltage supply to TP7 and TE7 through a 100
ohm 1/4W resistor. Adjust the DC voltage to 23 VDC. The
receiver should shutdown, losing raster and sound. Then the
receiver should turn off automatically. This reaction indicates
that the Hold-Down circuit is functioning properly. If the
receiver does not shutdown, a malfunction is indicated and its
cause must be found and corrected.
4. To obtain picture again, remove the DC Supply and wait a few
minutes. Now turn on the receiver.
— 8 —
SERVICE ADJUSTMENTS (Continued)
VIDEO INPUT LEVEL ADJUSTMENT
Note: Video Input Level adjustment affects brightness level.When
Video Input Level adjustment is made, brightness level
must be checked.
1. Connect video signal generator output (1 Vp-p terminated at
75 ohms) to VIDEO INPUT JACK.
2. Set TV to Game Mode.
3. Connect scope to TP16A and ground.
4. Adjust Video Input Level (VR1023) for 2.0 ± 0.2 VDC.
5. Set TV to TV Mode, Picture Controls to Auto levels.
Check brightness and contrast on several active channels. If
brightness or contrast is incorrect, reset bright level.
SOUND ADJUSTMENT
1. Connect Voltmeter – lead to ground and + lead TP 20 (FM
DET OUT) on main board.
2. Tune receiver to an active channel and fine tune to obtain the
best picture.
3. Confirm D.V.M. reading of 3.85 ± 0.2 VDC.
4. I f the voltage is out of this range, adjust Sound I.F. Transformer
(T131) for 3.85 ± 0.2 VDC.
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