Sanyo ds19330 schematic

AS
FILE NO.
SERVICE MANUAL (SUPPLEMENT)
Remote Control Color Television
DS19330 (U.S.A.)
(CANADA)
Chassis No. 19330-00
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.
G8MDA, PRODUCT CODE 111363880
REFERENCE No. SS780042
THIS CHASSIS IS SIMILAR TO MODEL DS19310, CHASSIS NUMBER 1931 0-04.SERVICE INFORMATION GIVEN IN THIS MANUAL IS ONLY THE DIFFERENCE INFORMATION FROM MODEL DS19310, CHASSIS NUMBER 19310-04. FOR ADDITIONAL SERVICE INFORMATION, REFER TO THE SERVICE MANUAL FOR CHASSIS NUMBER 19310-04 USED IN MODEL DS19310 (SM5110224-04).
AS
MENU
CH
VO
L
POWER
VID
EO
IN
AUDIO IN
1 610 278 9713 CABINET FRONT ASSY 610 303 8988 CAB FRONT ASSY 4 610 289 2581 CABINET BACK 610 307 5297 CABINET BACK 6 610 289 3731 BUTTON UNIT 610 304 5245 BUTTON UNIT 7 610 289 5148 CAP RC 610 267 0851 CAP RC
610 289 8071 DEC SHEET N/A NOT USED 610 297 8810 OWNER’S MANUAL 610 304 4095 OWNER’S MANUAL
DIFFERENCES
M
ODEL DS19330 (Chassis No. 19330-00)
SAME AS MODEL
DS19310 (Chassis
No. 19310-04) EXCEPT:
1. IN THE CABINET / ACCESSORY PARTS LIST
MODEL DS19310 (Chassis No. 19310-04)
MODEL DS19330 (Chassis No. 19330-00)
Part No. Description
KEY NO.
Part No. Description
April / 2003 / 2000 SMC
Printed in U.S.A.
For parts or service contact
21605 Plummer Street Chatsworth, CA 91311 (U.S.A.)
300 Applewood Crescent, Concord, Ontario L4K 5C7 (CANADA)
SANYO FISHER SERVICE
4
5
2
3
1
6
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VO
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A
S
POWER
V
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EO
IN
AUDIO
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Specifications
Power Rating . . . . . . . . . . . . . . . . . . . . . 120V, 60Hz
58W (Avg), 1.4A (Max)
Antenna Input Impedance. . . . . . . . . . . . . . . . . 75
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/CH
Intermediate Frequency
Picture IF Carrier. . . . . . . . . . . . . . . . . . 45.75MHz
Sound IF Carrier . . . . . . . . . . . . . . . . . . 41.25MHz
Color Sub Carrier . . . . . . . . . . . . . . . . . 42.17MHz
Picture Tube. . . . . . . . . . . . . . . . . . A48KRD82X(DT)
Semiconductors
Integrated Circuits. . . . . . . . . . . . . . . . . . . . . . . . 7
Transistors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Except within Tuner and RC Pre-Amp.
Cabinet Dimensions
Width. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488mm
Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452mm
Depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467mm
REFERENCE No. SM5110224-04
DS19310, G8EHM, PRODUCT CODE 111355483
AS
FILE NO.
SM5110224
REF : No.
COLOR TELEVISION
Notice
CORRECTION SERVICE FLASH
PRODUCTION CHANGE ADD INFORMATION
Please add this notice to the Service Manual listed below.
REVISION 04
Category :
DS19310
Model:
U.S.A. / CANADA
Destination:
MARCH / 15 / 2002
Date:
19310-04
Effective from : Chassis No.
NOTE: Match the Chassis No. on the unit’s back cover with the Chassis No. in the Service Manual.
If the Service Manual Chassis No. does not match the unit’s, additional Service Literature is
required. This chassis is similar to Chassis No. 19310-00, however, all Service Information is given in this Notice for Chassis No. 19310-04 used in Model DS19310.
Contents
Safety Instructions . . . . . . . . . . . . . . . . . . 2
Service Adjustments. . . . . . . . . . . . . . 3 - 8
Service Hints. . . . . . . . . . . . . . . . . . . . . . . 9
Purity and Convergence . . . . . . . . . 10 - 11
Mechanical Disassemblies. . . . . . . . . . . 12
Chassis Electrical Parts List . . . . . . 13 - 18
Cabinet Parts List . . . . . . . . . . . . . . . . . . 19
Component and Test Point
Locations . . . . . . . . . . . . . . . . . . . 20 - 23
Schematic Insert . . . . . . . . . . . . . . . 25 - 32
Schematic Notes . . . . . . . . . . . . . . . . . 25
Pin Layouts . . . . . . . . . . . . . . . . . . . . . 25
Capacitor and Resistor Codes . . . . . . 25
Block Diagram. . . . . . . . . . . . . . . 26 - 27
Voltage Charts . . . . . . . . . . . . . . . 26 - 27
Waveforms. . . . . . . . . . . . . . . . . . . . . . 28
Schematic Diagrams . . . . . . . . . . 29 - 32
— 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 X-RADIATION 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 VOL T AGE 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 HOLD­DOWN 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
READING SHOULD NOT EXCEED 750 mV.
AC VOLTMETER
(5000 ohms per volt or more sensitivity)
TELEVISION
RECEIVER
Good earth ground such as a water pipe, conduit, etc.
AC OUTLET
1500 ohm
10 watt
0.15 µF 150V AC
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.)
2. Service Adjustments:
Press the or key to select the desired service menu item 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 AD JUSTMENTS
— 3 —
OPT XX
Figure 1. Service Menu Display
TITLE
HEXADECIMAL DATA
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. 4 VS (V Size), No. 7 VLN (V Linearity) No. 10 VSC (V S Cor.)
No. 21 SBI (Sub Bias), No. 32 BSG (Blk Stk Gain), No. 42 RAD (RF AGC Delay), No. 49 STI (Sub Tint), No. 50 SSH (Sub Sharp), and No. 51 OPT (Option 1) should be set up for proper TV operation before attempting the service adjust­ments.
Bus data is in the hexadecimal format.
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. 4 VS (V Size) with ▲ or ▼ key. Adjust the data with + or – key for 50.
4. Select No. 7 VLN (V Linearity) with or key. Adjust the data with + or – key for 15.
5. Select No. 10 VSC (V S Correction) with ▲ or ▼ key. Adjust the data with + or – key for 0A.
6. Select No. 32 BSG (Blk Stk Gain) with or key. Adjust the data with + or – key for 02.
7. Select No. 42 RAD (RF AGC Delay) with or key. Adjust the data with + or – key for 20.
8. Select No. 49 STI (Sub Tint) with ▲ or ▼ key. Adjust the data with + or – key for 17.
9. Select No. 51 OPT (Option 1 with ▲ or ▼ key. Adjust the data with + or – key for 04.
10. Press the MENU key to turn off the Service Menu display.
No. TITLE
INITIAL REFERENCE INITIAL SETUP
RANGE OF DATA FUNCTION
DATA DATA 1 HFR 1E 1E 00~3F Horizontal Frequency 2 AFC 00 00 00, 01 AFC Gain and Gate 3 HP 0E 0E* 00~1F Horizontal Phase (Horizontal Centering) 4 VS 32 50* 00~7F Vertical Size 5 VPO 05 05 00~3F Vertical Position 6 VSP 00 00 00, 01 Vertical Set Up (Sync Sensitivity) 7 VLN 13 15* 00~1F Vertical Linearity 8 CRS 00 00 00~03 Cross B/W 9 GRY 01 01 00, 01 Grey Mode
10 VSC 08 0A* 00~1F Vertical S Correction 11 HBR 03 03 00~07 Horizontal Blanking Right 12 HBL 04 04 00~07 Horizontal Blanking Left 13 CDM 00 00 00, 01 Color Difference Mode 14 VC 07 07 00~07 Vertical Compression 15 RB 00 00 00~FF Red Bias 16 GB 00 00 00~FF Green Bias 17 BB 00 00 00~FF Blue Bias 18 RD 40 40 00~7F Red Drive 19 GD 08 08 00~0F Green Drive Reduction 20 BD 40 40 00~7F Blue Drive 21 SBI 30 30 00~7F Sub Bias 22 OSD 02 02 00~03 On Screen Display Contrast 23 POS 01 01 00, 01 Preshoot Overshoot Switch 24 FLS 01 01 00, 01 Filter System 25 CKO 03 03 00~07 Color Killer operation 26 GYA 00 00 00, 01 G-Y Angle 27 CRG 02 02 00~03 Corring Gain 28 PRE 03 03 00~03 Preshoot Adjust 29 WP 01 01 00, 01 White Peak Limiter 01: OFF 00: ON 30 FSW 00 00 00, o1 Flyback Blanking Switch 31 VBL 00 00 00, 01 Vertical Blanking Switch 32 BSG 01 02* 00~03 Black Stretch Gain 33 BSS 01 01 00~03 Black Stretch Start 34 DCR 01 01 00~03 DC Reset 35 YGM 01 01 00~03 Y Gamma Start 36 CBP 00 00 00, 01 C Bypass 37 AF 01 01 00, 01 Auto Flesh 0: OFF 1: ON 38 BAT 04 04 00~07 Bright ABL Threshold 39 MSD 00 00 00, 01 Mid Stop Defeat 40 ABL 00 00 00, 01 ABL Defeat 0: OFF 1: ON 41 RYA 02 02 00~0F R-Y/B-Y Angle 42 RAD 0F 20* 00~3F RF AGC Delay 43 IAS 00 00 00. 01 IF AGC Switch 0: TV (Normal) 1: AV (IF Gain Minimum) 44 FMM 00 00 00, 01 FM Mute
— 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 45 FL 0F 0F 00~1F FM Level 46 VL 05 05 00~07 Video Level 47 SB 20 20 00~3F Sub Bright 48 SCO 0A 0A 00~1F Sub Color 49 STI 16 17* 00~1F Sub-Tint 50 SSH 12 0C* 00~1F Sub Sharpness 51 OPT 00 04* 00~FF Option 1 (See Note 1 below.) 52 OPT2 00 00 00~FF Option 2 (See Note 2 below.) 53 HR 13 13 00~3F On Screen Display Horizontal Position 54 SBO 05 05 00~FF Sub Bright Offset
55 DRV
R40 R40 00~7F Red Drive Adjustment (See Note 3 below.) R40 R40 00~7F Blue Drive Adjustment (See Note 3 below.)
0 0 00~FF Red Bias Adjustment (See Note 4 below.)
56 0 0 00~FF Green Bias Adjustment (See Note 4 below.)
0 0 00~FF Blue Bias Adjustment (See Note 4 below.)
57 R00 0 0 00~FF N/A
↓↓
115 R48 0 0 00~FF N/A
— 5 —
Table 1. ON-SCREEN SERVICE MENU (Continued)
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.)
PROGRAM CODE
The microprossesor 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 Code must be correct.
Note 1. Option Data (NO. 51 OPT) should be set to hexa­decimal 04. 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 (NO. 52 OPT2) should be set to hexa­decimal 00. If this program code is wrong the TV will not
operate properly.
Note 3. Red/Blue Drive Adjustments in Service Menu NO. 55 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. 18 RD and 20 BD 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
Note 4. Red/Green/Blue Bias Adjustments in Service Menu NO. 56: 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. 15 RB, No. 16 GB, and No. 17 BB automatically.
BIT FUNCTION
DATA
01
0, 1 TV/HOTEL/MONITOR NOT USED 2 VIDEO INPUT NONE YES 3, 4 CLOCK NOT USED 5 STEREO/MONO NOT USED 6, 7 SURROUND NOT USED
BIT FUNCTION
DATA
01 0 V–GUIDE YES NONE 1 COLOR ENHANCER NOT USED 2 INITIAL CHANNEL NOT USED 3 NOT USED NOT USED 4 PIP NOT USED 5 AV1/AV1, AV2 NOT USED 6 TONE/BASS, TREBLE NOT USED 7 GAME KEY NONE YES
SERVICE AD JUSTMENTS (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 VOL T AGE CHECK
Connect Voltmeter + lead to TJ1 135V and – lead to ground (TE7). Connect receiver to AC 120V line. Tune receiver to an active channel. Reset the picture controls to the AUTO level. Voltage must measure between +133.0V and +137.0V. 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. 3 HP (Horizontal Phase) with or ▼ key.
6. Adjust the data with + or – key for 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. 4 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. C he ck that picture is in the center of TV screen. If picture center is too low, change resistor R513 (3.9K ohm, 1/6W) to a 470 ohm, 1W. If picture center is too high, add resistor R512 (470 ohm, 1W).
GRA Y SCALE ADJUS TMENT
1. Set the picture controls to the Auto levels (use MENU key and or key or RESET key).
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. 15 RB (Red Bias), NO. 16 GB (Green Bias), and NO. 17 BB (Blue Bias) with or key and set each data to 0 with + or – key.
5. Select NO. 18 RD (Red Drive) and NO. 20 BD (Blue Drive) with or key and set each data to 40 with + or – key.
6. Set NO. 19 GD (Green Drive Reduction) data to 08, NO. 47 SB (Sub Brightness) data to 20, NO. 48 SCO (Sub Color) data to 0A, NO. 49 STI (Sub Tint) to 17 and NO. 50 SSH (Sub Sharpness) data to 0C with or ,and + or – keys.
7. Turn Screen Control (T402) to minimum (fully counter­clockwise).
8. Select the Service Menu NO. 56 (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.)
11. Select the Service Menu NO. 55 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.)
13. Check for proper grayscale at all brightness levels. To turn off the Service Menu display, press the MENU key.
Note: I f Gr ayscale Adjustment is made after picture tube
replacement, check Brightness Level Adjustment.
FOCUS ADJUSTMENT
Adjust focus control (T402) for well defined scanning lines.
CAUTION
FOR CONTINUED PROTECTION AGAINST A RISK 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.
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’ functions in
Service Menu NO. 56
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’ functions in
Service Menu NO. 55 DRV
FOR RED DRIVE ADJUSTMENT
FOR BLUE DRIVE ADJUSTMENT
4A 125V
— 7 —
VCO AD JUSTMENT
Note: VCO must be adjusted after IC101 (Signal
Processor), IC802 (EEPROM) or T151 (VCO Coil) is replaced.
1. Tune receiver to an active channel.
2. Set the picture controls to the Auto level.
3. Connect digital voltmeter + lead to pin 58 of IC101 and – lead to ground (TE 7).
4. Confirm a reading of 3.6 ± 0.2 VDC.
5. If voltage is out of specifications adjust T151 for
3.6 ± 0.2 VDC.
RF AGC ADJUS TMENT
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. 42 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. Reset 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. 47 SB (Sub Brightness) with or key.
8. Adjust the data with + or – key for 820 mVDC.
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.
HIGH VOL T AGE 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. Reset 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.
HIGH VOL T AGE CHECK
Note: +B (+135V) Voltage Check and Grayscale Adjustment
must be completed before attempting High Voltage Check.
1. Connect high voltage voltmeter – 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.
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