JVC AV-28t77 Schematic

SERVICE MANUAL

COLOUR TELEVISION

YA06020043

AV-28R4SK, AV-28T4BK, AV-28T4SK,

AV-28T4SP, AV-28T4BR, AV-28T4SR,

AV-28T77SK, AV-32R4SK, AV-32T4SK,

AV-32T4SP, AV-32T4SR, AV-32T77SK

BASIC CHASSIS

TV OK

.T/L

AV-28R4SK, AV-28T4BK, AV-28T4SK, AV-28T4SP, AV-28T4BR, AV-28T4SR,

AV-28T77SK

AV-32T77SK AV-32R4SK, AV-32T4SK, AV-32T4SP, AV-32T4SR

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18

5 TROUBLE SHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-34

No.YA060

2004/3

SPECIFICATION

Contents

AV-28T4SK

Items

Dimensions ( W × H × D ) 85.4cm × 50.8cm × 49.7cm 85.4cm × 50.7cm × 49.7cm

Mass 42.0kg 42.0kg

TV RF System CCIR ( I ) CCIR (B/G, I, L) Colour System PAL

NTSC3.58 / NTSC4.43 (Only EXT mode)

Stereo System NICAM ( I ) A2 (B/G)

Receiving Frequency

French CATV --- 116MHz - 172MHz

Intermediate Frequency

Colour Sub Carrier Frequency

Teletext System FLOF (Fastext level 2.5)

Power Input AC 220V~AC240V, 50Hz Power Consumption 125W(Max) / 115W(Avg)

Picture Tube Visible size : 66cm [measured diagonally] (H : 58.3cm × V : 33.0cm) High Voltage 31.0kV (+1kV / -1.5kV) (at zero beam current) Speaker MAIN : 6.5cm × 13cm oval type × 2

Audio Power Output MAIN : 10W + 10W

Aerial Input Terminal 75 Ω unbalanced, coaxial EXT-1 / EXT-2 / EXT-3

(Input / Output) EXT-4 S-Video Mini-DIN 4-pin × 1

Audio Out (variable) 0 - 1000V(rms), low impedance, RCA pin jack × 2 Surround Rear Terminal 7.5W + 7.5W, 8 Ω --- Headphone Jack Stereo mini jack, Ø3.5mm × 1 Remote Control Unit RM-C1502-1C

VHF --- 47MHz - 470MHz UHF 470MHz - 862MHz

VIF 38.9MHz ( I ) 38.9MHz (B/G, I, L)

SIF 32.9MHz (6.0MHz :I) 33.4MHz (5.5MHz :B/G)

PAL 4.43MHz

SECAM --- 4.40625MHz / 4.25MHz

NTSC 3.58MHz / 4.43MHz

WST(Standard system)

Standby : 2.7W

CENTER : 4cm × 16cm oval type × 2 SUB WOOFER : 13cm round type × 1

CENTER : 10W SUB WOOFER : 18W

21-pin Euro connector (SCART socket × 3)

Y : 1V(p-p) positive, negative sync 75Ω

C : 0.286V(p-p) (burst signal) 75Ω Video 1V(p-p) positive, negative sync provided, 75Ω, RCA pin jack × 1 Audio 500mV(rms) (-4dBs), high impedance, RCA pin jack × 2

(AA/R6 dry cell battery × 2)

AV-28R4SK

85.4cm × 50.7cm × 48.9cm [AV-28T77SK]

39.0kg [AV-28T77SK]

120W(Max) / 110W(Avg) Standby : 2.7W

6.5cm × 13cm oval type × 2

10W + 10W

RM-C1502-1C (Silver) RM-C1502B-1C (Black) (AA/R6 dry cell battery × 2)

Design & specifications are subject to change without notice.

[AV-28R4SK]

This product is manufactured under license from Dolby Laboratories Licensing Corporation. "Dolby" and the double-D symbol are trademarks of Dolby Laboratories Licensing Corporation.

AV-28T4BK AV-28T4SR AV-28T4BR

AV-28T77SK

AV-28T4SP

85.4cm × 50.8cm × 49.3cm

39.0kg

PAL SECAM NTSC3.58 / NTSC4.43 (Only EXT mode)

NICAM (B/G, I, L)

220MHz - 469MHz

33.9MHz (L')

32.9MHz ( 6.0MHz:I )

32.4MHz (6.5MHz :L)

TOP (German system) FLOF (Fastext level 2.5 720P) WST (Standard system)

RM-C1502-1C (AA/R6 dry cell battery × 2)

---

1-2 (No.YA060)

Contents

Items

Dimensions ( W × H × D ) 94.8cm × 56.2cm × 55.4cm 94.8cm × 56.2cm × 55.4cm

Mass 56.0kg 56.0kg

TV RF System CCIR ( I ) CCIR (B/G, I, L) Colour System PAL

NTSC3.58 / NTSC4.43 (Only EXT mode)

Stereo System NICAM ( I ) A2 (B/G)

Receiving Frequency

French CATV --- 116MHz - 172MHz

Intermediate Frequency

Colour Sub Carrier Frequency

Teletext System FLOF (Fastext level 2.5)

Power Input AC 220V~AC240V, 50Hz Power Consumption 125W(Max) / 115W(Avg)

Picture Tube Visible size : 76cm [measured diagonally] (H : 67.4cm × V : 38.4cm) High Voltage 31.0kV (+1kV / -1.5kV) (at zero beam current) Speaker MAIN : 6.5cm × 13cm oval type × 2

Audio Power Output MAIN : 10W + 10W

Aerial Input Terminal 75 Ω unbalanced, coaxial EXT-1 / EXT-2 / EXT-3

(Input / Output) EXT-4 S-Video Mini-DIN 4-pin × 1

Audio Out (variable) 0 - 1000V(rms), low impedance, RCA pin jack × 2 Surround Rear Terminal 7.5W + 7.5W, 8 Ω --- Headphone Jack Stereo mini jack (Ø3.5mm × 1) Remote Control Unit RM-C1502-1C (AA/R6 dry cell battery × 2)

VHF --- 47MHz - 470MHz UHF 470MHz - 862MHz

VIF 38.9MHz ( I ) 38.9MHz (B/G, I, L)

SIF 32.9MHz (6.0MHz :I) 33.4MHz (5.5MHz :B/G)

PAL 4.43MHz

SECAM --- 4.40625MHz / 4.25MHz

NTSC 3.58MHz / 4.43MHz

WST(Standard system)

Standby : 2.7W

CENTER : 4cm × 16cm oval type × 2 SUB WOOFER : 13cm round type × 1

CENTER : 10W SUB WOOFER : 18W

21-pin Euro connector (SCART socket × 3)

Y : 1V(p-p) positive, negative sync 75Ω

C : 0.286V(p-p) (burst signal) 75Ω Video 1V(p-p) positive, negative sync provided, 75Ω, RCA pin jack × 1 Audio 500mV(rms) (-4dBs), high impedance, RCA pin jack × 2

AV-32R4SK

94.6cm × 56.2cm × 54.7cm [AV-32T77SK]

53.0kg [AV-32T77SK]

120W(Max) / 110W(Avg) Standby : 2.7W

6.5cm × 13cm oval type × 2

10W + 10W

AV-32T4SK AV-32T4SR

AV-32T77SK

AV-32T4SP

94.8cm × 56.2cm × 55.0cm

53.0kg

PAL SECAM NTSC3.58 / NTSC4.43 (Only EXT mode)

NICAM (B/G, I, L)

220MHz - 469MHz

33.9MHz (L')

32.9MHz ( 6.0MHz:I )

32.4MHz (6.5MHz :L)

TOP (German system) FLOF (Fastext level 2.5 720P) WST (Standard system)

Design & specifications are subject to change without notice.

[AV-32R4SK]

This product is manufactured under license from Dolby Laboratories Licensing Corporation. "Dolby" and the double-D symbol are trademarks of Dolby Laboratories Licensing Corporation.

---

(No.YA060)1-3

SECTION 1

PRECAUTION

1.1 SAFETY PRECAUTIONS [EXCEPT FOR UK]

(1) The design of this product contains special hardware,

many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only.

(2) Alterations of the design or circuitry of the products should

not be made. Any design alterations or additions will void the manufacturer's warranty and will further relieve the manufacturer of responsibility for personal injury or property damage resulting therefrom.

(3) Many electrical and mechanical parts in the products have

special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the parts list of Service manual. Electrical components

having such features are identified by shading on the schematics and by ( ) on the parts list in Service manual. The use of a substitute replacement which does

not have the same safety characteristics as the recommended replacement part shown in the parts list of Service manual may cause shock, fire, or other hazards.

(4) Don't short between the LIVE side ground and

ISOLATED (NEUTRAL) side ground or EARTH side ground when repairing.

Some model's power circuit is partly different in the GND. The difference of the GND is shown by the LIVE : ( ) side GND, the ISOLATED (NEUTRAL) : ( ) side GND and EARTH : ( ) side GND. Don't short between the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND and never measure the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND at the same time with a measuring apparatus (oscilloscope etc.). If above note will not be kept, a fuse or any parts will be broken.

(5) If any repair has been made to the chassis, it is

recommended that the B1 setting should be checked or adjusted (See B1 POWER SUPPLY check).

(6) The high voltage applied to the picture tube must conform

with that specified in Service manual. Excessive high voltage can cause an increase in X-Ray emission, arcing and possible component damage, therefore operation under excessive high voltage conditions should be kept to a minimum, or should be prevented. If severe arcing occurs, remove the AC power immediately and determine the cause by visual inspection (incorrect installation, cracked or melted high voltage harness, poor soldering, etc.). To maintain the proper minimum level of soft X-Ray emission, components in the high voltage circuitry including the picture tube must be the exact replacements or alternatives approved by the manufacturer of the complete product.

(7) Do not check high voltage by drawing an arc. Use a high

voltage meter or a high voltage probe with a VTVM. Discharge the picture tube before attempting meter connection, by connecting a clip lead to the ground frame

and connecting the other end of the lead through a 10kΩ

2W resistor to the anode button.

(8) When service is required, observe the original lead dress.

Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those components that indicate evidence of overheating should be replaced. Always use the manufacturer's replacement components.

(9) Isolation Check (Safety for Electrical Shock Hazard)

After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/audio input and output terminals, Control knobs, metal cabinet, screw heads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.

a) Dielectric Strength Test

The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed metal part having a return path to the chassis should withstand a voltage of 3000V AC (r.m.s.) for a period of one second. (. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or more, for a period of one second.) This method of test requires a test equipment not generally found in the service trade.

b) Leakage Current Check

Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a "Leakage Current Tester", measure the leakage current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.2mA AC (r.m.s.).

Alternate Check Method

Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Use

an AC voltmeter having 1000Ω per volt or more sensitivity in the following manner. Connect a 1500Ω 10W resistor paralleled by a 0.15µF AC-type capacitor

between an exposed metal part and a known good earth ground (water pipe, etc.). Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to

0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).

AC VOLTMETER (HAVING 1000 /V, OR MORE SENSITIVITY)

0.15 F AC-TYPE

PLACE THIS PROBE

1500 10W

GOOD EARTH GROUND

ON EACH EXPOSED ME TAL PAR T

1-4 (No.YA060)

1.2 SAFETY PRECAUTIONS [FOR UK]

(1) The design of this product contains special hardware and many circuits and components specially for safety purposes. For

continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only.

(2) Alterations of the design or circuitry of the product should not be made. Any design alterations or additions will void the

manufacturer's warranty and will further relieve the manufacturer of responsibility for personal injury or property damage resulting therefrom.

(3) Many electrical and mechanical parts in the product have special safety-related characteristics. These characteristics are often

not evident from visual inspection nor can the protection afforded by them necessary be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement part shown in the Parts List of Service Manual may cause shock, fire, or other hazards.

(4) The leads in the products are routed and dressed with ties, clamps, tubing’s, barriers and the like to be separated from live parts,

high temperature parts, moving parts and / or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.

WARNING

(1) The equipment has been designed and manufactured to meet international safety standards. (2) It is the legal responsibility of the repairer to ensure that these safety standards are maintained. (3) Repairs must be made in accordance with the relevant safety standards. (4) It is essential that safety critical components are replaced by approved parts. (5) If mains voltage selector is provided, check setting for local voltage.

(No.YA060)1-5

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

• New chassis design enable use of an interactive on screen control.

• The TELETEXT SYSTEM has a built-in FASTEXT (UK system), TOP (German system) and WST (world standard system) system.

2.2 21-pin Euro connector (SCART) : EXT-1/EXT-2/EXT-3

Pin No. Signal designation Matching value EXT-1 EXT-2 EXT-3

1 AUDIO R output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT) Not used

2 AUDIO R input 500mV(rms) (Nominal), High impedance Used (R1) Used (R2) Used (R3)

3 AUDIO L output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT) Not used

4 AUDIO GND Used Used Used

5 GND (B) Used Used Used

6 AUDIO L input 500mV(rms) (Nominal), High impedance Used (L1) Used (L2) Used (L3)

7 B input 700mV

FUNCTION SW

(SLOW SW)

Low : 0V-3V High : 8V-12V, High impedance

, 75Ω Used Used Not used

(B-W)

9 GND (G) Used Used Used

10 SCL / T-V LINK Not used

11 G input 700mV

, 75Ω Used Used Not used

(B-W)

12 SDA Not used Used (SDA2) Not used

13 GND (R) Used Used Used

14 GND (YS) Used Not used Not used

15 R / C input

R : 700mV C : 300mV

(B-W) (P-P)

, 75Ω

16 Ys input (FAST SW) Low : 0V-0.4V, High : 1V-3V, 75Ω Used Used Not used

17 GND (VIDEO output) Used Used Used

18 GND (VIDEO input) Used Used Used

19 VIDEO output 1V

20 VIDEO / Y input 1V

(Negative sync), 75Ω Used (TV OUT) Used (LINE OUT) Not used

(P-P)

(Negative sync), 75Ω Used Used Used

(P-P)

21 COMMON GND Used Used Used

• Because this TV unit corresponds to multiplex broadcast, users can enjoy music programs and sporting events with live realism. In addition, BILINGUAL programs can be heard in their original language.

• Users can make VCR dubbing of picture and sound by controlling the AV selector to select an optional source at the EXT-2 output.

Used Used Used

Used

(SCL2 / TV-LINK)

Not used

Used (R) Used (C2/R) Used (C3)

(P-P= Peak to Peak, B-W= Blanking to white peak)

[Pin assignment]

20 18 16 14 12 10 8 6 4 2

21 19 17 15 13 11 9 7 5 3 1

1-6 (No.YA060)

2.3 MAIN DIFFERENCE LIST

Item AV-28R4SK AV-28T4SK AV-28T4BK AV-28T4SR AV-28T4BR AV-28T77SK AV-28T4SP

CABINET TYPE A ←←←←BA CABINET COLOUR Silver ← Black Silver Black Silver Silver

DESTINATION England England England Ireland Ireland England Germany

Belgium

France

Switzerand

Austria

Italy

Spain Portugal Sweden

Denmark

Finland Norway Greece

DOLBY SORROUND YES NO ←←←←← SUB WOOFER YES NO ←←←←← POWER PLUG UK type(3pin) ←←←←←EU type(2pin) S VIDEO INPUT YES ←←←←←NO

Item AV-32R4SK AV-32T4SK AV-32T4SR AV-32T77SK AV-32T4SP

CABINET TYPE A ←←BA

DESTINATION England England Ireland England Germany

Belgium

France

Switzerand

Austria

Italy

Spain Portugal Sweden

Denmark

Finland Norway Greece

DOLBY SORROUND YES NO ←←← SUB WOOFER YES NO ←←← POWER PLUG UK type(3pin) ←←←EU type(2pin) S VIDEO INPUT YES ←←←NO

CABINET TYPE

B typeA type

(No.YA060)1-7

2.4 TECHNINAL INFORMATION

2.4.1 MAIN MI-COM (CPU) PIN FUNCTION

Pin No.

1 VssP2 -- GND 65 SVM O SVM output 2 VssC4 -- GND 66 FbiSo I/O Flyback input/SC output 3 V1.8C4 -- 1.8VD 67 Hout O H output 4 V3.3A3 -- 3.3V 68 VssComb -- GND for comb filter 5 VrefP_Sdac -- 3.3V 69 V5Comb -- 5V for comb filter 6 VrefN_Sdac -- 0V 70 Vin/R2/Pr I V-input for YUV 7 VrefP_Sdac -- 3.3V 71 Uin/B2/Pb I U-input for YUV 8 VrefN_Sdac -- 0V 72 Yin/G2/Y I Y-input for YUV

9 VrefP_Sdac -- 3.3V 73 Ysync I Y-input for SyncSep 10 XtalIn I XTALIN 74 Yout O Y-out 11 XtalOut O XTALOUT 75 Uout/INSSW2 I/O U-out (2nd RGB/YPbPr insertion input) 12 VssA1 -- GND 76 Vout/Swo1 O NC 13 Vguard/Swo I/O VGUARD or I/O switch 77 INSSW3 I 3rd RGB/YPbPr insertion 14 DecDig -- Decoupling Digital Supply 78 R3/Pr I 3rd R in/Pr in 15 V5P1 -- 1st Supply 5V 79 G3/Y I 3rd G in/Y in 16 Phi2 -- Phase-2 filter 80 B3/Pb I 3rd B in/Pb in 17 Phi1 -- Phase-1 filter 81 Gnd3 -- GND3 18 Gnd1 -- GND1 82 V5P3 -- 3rd supply 19 SecPll -- SECAM PLL Decoupling 83 BCL I BCL input 20 Dec8G -- Bandgap decoupling 84 BLKIN I Black current input 21 Ewd/Avl O E/W Drive or AVL cap. 85 Rout O Red output 22 Vdb O V. Drive B output 86 Gout O Green output 23 Vda O V. Drive A output 87 Bout O Blue output 24 Vif1 I IF input 1 88 V3.3A1 -- 3.3V analog 25 Vif2 I IF input 2 89 RefAdN -- Negative ref. voltage 26 Vsc -- Vertical sawtooth cap. 90 V3.3RefAdP -- Positive ref. voltage 27 Iref I Ref. current input 91 RefAd -- Reference voltage for ADC 28 GndIF -- GND IF 92 GndA -- GND 29 Sif1 I SIF input 1 / DVB input 1 93 V1.8A I Supply for ADC 30 Sif2 I SIF input 2 / DVB input 2 94 V3.3A2 I Supply for SDAC 31 Agc O Tu AGC output 95 VssADC -- GND for Temp. sensor 32 EHT I EHT/overvoltage protect 96 V1.8ADC -- Supply video ADC 33 Ssif/RefIn/Avl/RefOut O L/OTHER 97 IntO I REMOCON 34 AudioIn5L I Audio 5 input (Left) 98 P10/Int1 I AV_LINK IN 35 AudioIn5R I Audio 5 input (Right) 99 P11/TO O AV_LINK OUT 36 AudOutSL O Audio output (Left) 100 V1.8C2 -- digital 1.8V 37 AudOutSR O Audio output (Right) 101 VssC2 -- GND 38 DecsDem -- decoupling sound demod. 102 P04/I2SWs I/O (I2S_WS) 39 QssO/AmO/AudeEm O QSSO/AMout/deemphasis 103 P03/I2SClk I/O (I2S_CLK) 40 Gnd2 -- GND2 104 P02/I2SDo2 O L/R_OTH (I2S_Dout2) 41 PllIf -- IF PLL loop filter 105 P01/I2SDo1 O D/A_RST (I2S_Dout1) 42 SifAgc -- AGC SIF / int-extAGCforDVB 106 P00/I2SDI1 I H/P DET 43 IfVo/FmRo/DvbO O DVBout/IFvideo/FMout 107 P13/T1 O POWER 44 FmRo/DvbO O DVBout/FMout 108 SCL1 I/O SCL1 45 V8AudioSwitches -- 8V for Audio SW. 109 SDA1 I/O SDA1 46 AgcSsif -- AGC cap.2nd SIF 110 V3.3P -- 3.3V 47 V5P2 -- 2nd supply 5V 111 P20/TPwm O ROTATION (or N/S CANCEL) 48 SVO/IfVo/Cvbsl I/O IF vout/selCVBSo/CVBSin 112 P21/Pwm0 O (N/S_CEN/OTH) 49 Audio4InL I Audio 4 input (Left) 113 P22/Pwm1 O A_MUTE 50 Audio4InR I Audio 4 input (Right) 114 P23/Pwm2 O AMP_MUTE 51 Y4/Cvbs4 I CVBS4/Y4 input 115 P30/Adc0 I PROTECT 52 C4 I Chroma-4 input 116 P31/Adc1 O LED 53 Audio2InL I Audio 2 input (Left) 117 V1.8C1 -- 1.8V digital 54 Audio2InR I Audio 2 input (Right) 118 DecV1V8 -- Decoupling 1.8V 55 Cvbs2/Y I CVBS2/Y2 input 119 P32/Adc2 I KEY input 56 Audio3InL I Audio 3 input (Left) 120 P33/Adc3 I AGC input (ECO) 57 Audio3InR I Audio 3 input (Right) 121 VssC1+P1 I Digital GND m controller 58 Y3/Cvbs I CVBS3/Y3 input 122 P24/PWM3 O NC(SAW_SW) 59 C3 I Chroma-2/3 input 123 P25/PWM4 O RES_OUT 60 AudOutLsL I Audio output for AMP 124 V1.8C3 -- 1.8V digital 61 AudOutLsR I Audio output for AMP 125 VssC3 -- GND 62 AudOutHpL I HP L Audio output 126 P12/Int2 I POW_DET 63 AudOutHpR I HP-R Audio ouput 127 P14/RX I/O SDA0 64 CVBSO/PIP I/O CVBS/PIP output 128 P15/TX I/O SCL0

Pin name I/O Function

Pin No.

Pin name I/O Function

1-8 (No.YA060)

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

The illustration of Fig.5 is explained about AV-28R4SK/AV-32R4SK. In case of AV-28T Series or AV-32T Series MODELS, you disassemble in the same procedure using Fig.6.

3.1.1 REMOVING THE REAR COVER

(1) Unplug the power plug. (2) Remove the sub woofer cord from the AV TERMINAL

BOARD.

(3) Remove the SUB WOOFER UNIT on the top of the rear

cover upward. (4) Remove the 13 screws [A] as shown in Fig.5. (5) Withdraw the REAR COVER toward you.

3.1.2 REMOVING THE SIDE CONTROL JACK ASSY

• Remove the REAR COVER. (1) Remove the screw [B] as shown in Fig.5. (2) Slightly pull the SIDE CONTROL JACK ASSY toward you,

and detach the claw from FRONT CABINET. Then it can be removed.

(3) Then disconnect the connector [S], [F] and [K] as shown

in Fig 1.

3.1.3 REMOVING THE SIDE CONTROL PWB

• Remove the REAR COVER.

• Remove the SIDE CONTROL JACK ASSY. (1) Remove the 3 claws [C] from backside of the SIDE

CONTROL JACK ASSY as shown in Fig.1.

(2) Remove the SIDE CONTROL PWB from the SIDE

CONTROL JACK ASSY.

3.1.4 REMOVING THE AV TERMINAL BOARD

• Remove the REAR COVER. (1) Remove the 5 screws [G] as shown in Fig. 5. (2) Remove the 2 claws [H] at the bottom of the AV

TERMINAL BOARD as shown in Fig. 2.

(3) Shift the AV TERMINAL BOARD slightly in the direction of

arrow [I], and remove it as shown in Fig. 2.

(4) At first, expand the lever [K] with the SUB WOOFER connector,

and pull it out of connector jack as shown in Fig.3.

3.1.5 REMOVING THE MAIN CHASSIS

• Remove the REAR COVER. (1) Slightly raise the MAIN CHASSIS, and release the two claws

at the bottom of and both sides of the MAIN CHASSIS.

(2) Then withdraw the MAIN CHASSIS backward from the

front cabinet. (If necessary, detach the wire clamp, connectors etc.)

3.1.6 REMOVING THE MAIN SPEAKER

• Remove the REAR COVER. (1) Remove the 2 screws [E], and detach the MAIN SPEAKER

HOLDER as shown in Fig. 5. (When removing the screws [E] of the MAIN SPEAKER HOLDER, the lower side screw first, and then upper one.)

(2) Remove the 4 screws [F], which attached the MAIN

SPEAKER.

(3) Follow the same steps when disassemble the other hand

MAIN SPEAKER.

3.1.7 REMOVING THE CENTER SPEAKER

• Remove the REAR COVER.

• Remove the MAIN CHASSIS. (1) Remove the 2 screws [D] as shown in Fig. 5. (2) Remove the CENTER SPEAKER. If necessary, detach the

cables.

3.1.8 CHECKING THE PW BOARD

(1) Pull out the MAIN CHASSIS (Refer to REMOVING THE

MAIN CHASSIS).

(2) Erect the CHASSIS vertically with the HVT side facing up

so that you can easily check the back side of the PW board.

3.1.9 CAUTION

(1) When erecting the MAIN CHASSIS, be careful so that

there will be no contacting with other PWB.

(2) Before turning power on, make sure that the wire connector

is properly connected.

(3) When conducting a check with power supplied, be sure to

confirm that the CRT EARTH WIRE (BRAIDED ASS’Y) is connected to the CRT SOCKET PWB.

3.1.10 WIRE CLAMPING AND CABLE TYING

(1) Be sure to clamp the wire. (2) Never remove the cable tie used for tying the wires

together.Should it be inadvertently removed, be sure to tie the wires with a new cable tie.

Connector

SIDE

CONTROL

PWB

(Back view)

Fig.1

TERMINAL

BOARD

AV JACK PWB

Fig.2

SUB WOOFER CORD

AV TERMINAL BOARD

SUB WOOFER CORD

CONNECTOR for SUB WOOFER

Fig.3

FRONT

(No.YA060)1-9

3.1.11 REMOVING THE SUB WOOFER UNIT [AV-28R4SK / AV-32R4SK]

(1) Remove the 15 screws [L], remove the SP BOX B. (2) Remove the 4 screws [M], remove the SPEAKER. (3) Remove the 3 screws [N], remove BASS INT. DUCT.

CAUTION

• The woofer unit is mounted on the TV. Always move the TV and woofer unit together when removing the TV from the box, or when moving the woofer unit.

• If the TV is tilted during movement the woofer unit may fall. Be careful to keep the TV level when moving it.

• Do not grip the woofer unit when moving the TV.

• Do not place objects on the woofer unit duct.

SP BOX B

BASS INT. DUCT

SPEAKER

BASS INT. DUCT

TOP

SP BOX T

Fig.4

1-10 (No.YA060)

3.1.12 EXPLODED VIEW [AV-28R4SK and AV-32R4SK]

FRONT CABINET

MAIN SPEAKER

HOLDER

MAIN SPEAKER

CRT SOCKET PWB

FRONT CONTOL PWB

POWER & DEF. PWB

SIDE CONTROL PWB

SIDE CONTROL JACK ASSY

REAR COVER

CONTROL BASE

CENTER SPEAKER

AV JACK PWB

CLAW

MAIN PWB

DOLBY PWB

CLAW

SUB WOOFER UNIT

MAIN CHASSIS

AV TERMINAL BOARD

POWER CORD

Fig.5

SUB WOOFER CORD

(No.YA060)1-11

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