Sony KV-27EXR25 Service Manual

PHOTOFACT,

Technical Service Data

INDEX

Adjustment and Alignment Tools Convergence Adjustments

GridTrace

Important Parts Information Miscellaneous Adjustments

PartsList ................. 9,10,11

Photos

Troubleshooting Quick-Checks

PIP Adjustments

Placement Chart

Safety Precautions

Safety Related Adjustments Schematics

Terminal Guides and Notes Test Equipment Troubleshooting Tuner Terminal Guide

Tuner Voltage Chart

Location Guide

ABoard ....................

GBoard ....................

PBoard-TopBoard UlBoard

...................

ABoard ..................

CBoard ....................

Cabinet - Rear View CRT Neck Assembly

GBoard ....................

HBoard ....................

PBoard-BottomBoard .....

PBoard-TopBoard Ul

Board

U2Board .................

ABoard ....................

CBoard ....................

CRT Control D/A Converter

MTS Decoder PIP Power Supply Television

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..9

.7,8

.7,8 .7,8

.4,9

.8,9

.9 .8

.7 .9

.4 .2 .7

SONY

1 6

1 1 6 6

Model

W-27EXR25

(Chassis SCC-D50F-A)

Complete coverage

for servicing a television receiver...

Schematics Component

locations

Coverage includes this additional model and chassis:

MODEL

KV-27EXR20

Parts lists

Troubleshooting

guide

CHASSIS

SCC-DSOE-A

For Supplier Address,

See PHOTOFACT Annual Index

HOWARD

DECEMBER 1991 SET 2910

SAMS & COMPANY

TROUBLESHOOTING

POWER SUPPLY

Check AC Fuse F60 1.

F60

1 is open:

Check Bridge Rectifier Diodes (D601, and D602), Resistor

(R601), Capacitors. C601, C603 thru C606, Electrolytics C607,

and C650, Power Converter IC (IC65

(T604).

Apply 120V and check for If

17.OV

is missing:

Check Line Filters (T601, T602), Power Transformer (T604),

Capacitors C608, C609, Electrolytic C610, and

17.OV

is present, check for

15OV*

is missing:

Check the voltages, waveforms, and components associated

with Power Relay (RY601), and Relay Driver Transistor

(Q601), and D601.

Note: The set may be in shutdown. Refer to the “High Voltage

Shutdown” section of this Troubleshooting guide. If

15OV*

is present at the (+) lead of D601, check for the proper wa-

veform at pin 1 of IC65 1. If the waveform is missing:

Check the voltages, waveforms, and components associated with IC65 1, Transfer IC (IC652), Converter Transformer

(T651), and Soft Start Transistor

If the proper waveform is present at

Check the voltages, waveforms, and components associated with T6.5 1.

* Taken from isolated ground.

17.OV

at the (+) lead of D602.

15OV*

l),

at the (+)

(4612).

1 of IC65 1:

and Power Transformer

D602.

lead

of D601.

HORIZONTAL

Determine if the TV is in shutdown:

Refer to the “High Voltage Shutdown” section of this Troubleshooting guide.

If the TV is not in shutdown, inject a horizontal signal at the base of the Horizontal Output Transistor

If horizontal deflection is now present:

Check the voltages, waveforms, and components associated with pins Horizontal Drive Transistor (Q501).

If there is no horizontal sweep:

Check the voltages, waveforms, and components associated with check components associated with Diodes D5 17, D5 19, D520, D521, and D531 for defects.

The high voltage rectifier is part of T500 and if defective will effect the performance of the horizontal circuits.

If the horizontal oscillator is off frequency:

Check the voltages, waveforms, and components associated with AFC-DET Transistor (Q307), and Buffer Transistor

(Q3W.

Horizontal linearity or tors C506, C507, and C509 beiig defective.

37,39,41,

4502,

and Horizontal Output Transformer

foldover

(4502).

and 45 of Y/C/J IC (IC301), and

(T500),

problems may be caused by Capaci-

and

VERTICAL

Inject a vertical drive signal at pin 3 1 of Y/C/J IC (IC301). If vertical deflection is now present:

Check the voltages, waveforms, and components associated

with pins 29

thrn 34,38,

and 44 of IC301.

HIGH VOLTAGE SHUTDOWN

The

high voltage is monitored by Diode D531, rectifying pulses

from the Horizontal Output Transformer (T500). Should the high

,voltage increase, the rectified voltage at the cathode of Diode D531

will also increase, This will cause the voltage at pin 8 of Protect Module (PM501) to increase and turn on Protect Transistors (Q607,

4608)

which causes Relay Drive Transistor (4601) to turn off and

remove power from the set. To troubleshoot, remove Resistor R629 fom the circuit. Use a

for AC power. Start at 90VAC and increase as and repair the defect. Return R629 to the circuit.

Note: Care should be taken in defeating the high voltage shutdown circuit, as this may cause excessive X-radiation and damage the CRT,

TSOO,

and associated components. Monitor the high voltage

and troubleshoot.

necessary

variac

to locate

If there is still no vertical deflection:

Check the voltages, waveforms, and components associated

with Vert Out IC

Vertical linearity or ion, vertical feedback and

Check the voltages, waveforms, and components associated with Pin Correction IC (IC531) and Pin Out Transistor (4530).

Also check Electrolytics C328, C538, C540, C562, C563, and

C566 for defects.

(ICSOO).

foldover

bias

problems may be caused by pincush-

circuits:

IF-AGC

Inject a video signal at the IF input and check for video on the CRT. If video is present:

Check the tuner, tuner control, and tuner AFC circuits.

TROUBLESHOOTING

continued

If there is no video on the CRT, check for a video waveform at TP12.

If video is present at TP12:

Refer to the “Video” section of this Troubleshooting guide.

If there is no

Check the voltages, waveforms, and components associated with IF Module

A defective AGC circuit can cause an overloaded picture, excessive

snow or loss of audio and video. See the AGC Voltage Chart for AGC voltages with signal.

video

at TP12:

(IF201),

and AGC Mute Transistor

AGC Voltage Chart

pm 1 5.3v

(Q102).

IF201

SYNC

If there is no vertical or horizontal sync:

Check the voltages, waveforms, and components associated with Y Buffer Transistor (4301).

If there is no vertical sync:

Check the voltages, waveforms, and components associated with pins 38, and 44 of Y/C/J IC

(Q302), V/Sext

(Q3W.

If there is no horizontal sync:

Check the voltages, waveforms, and components associated with pins 41, and 45 of

2 Transitor

IC301.

(IC301), V/Sext

(Q303),

and

V/Sext

1 Transistor

3 Transistor

VIDEO

Check the voltages, waveforms, and components associated with pins Transistors (43 and Equalizer Transistor (43 and Gamma Comp 2 Transistor (4316).

If brightness is inadequate or

Check the voltages, waveforms, and components associated

with pin 5 of v901.

3,4,8,26,

lO,Q3 13),

and 27 of Y/C/J IC

Gamma Comp 1 Transistor (43

14).

camrot

(IC301),

Y Clamp Transistor (43

controll&

Buffer

15),

17),

CHROMA

Check for a chroma waveform at pm 5 of Y/C/J IC (X301). If the waveform is missing:

Check the voltages, waveforms, and components associated with Buffer Transistor of Comb Filter (CM1301).

If chroma waveform is present at pin 5 of er waveforms at pins

If these waveforms are missing:

Check the voltages, waveforms, and components associated with pins

Check the

If the proper wavforms are present at pins

Refer to the “Raster” section of this Troubleshooting guide.

5,6,7,19

3.58MHz

(Q417),

C-Switch IC

20,22,24

IC301.

thru 25 of

oscillator at pin 7 of

IC301.

(IC403),

IC30

1, cheek for the

IC301.

20,22,24

and pin 4

pmp

IC301:

RASTER

Check the CRT and CRT voltages. Cheek the voltages, waveforms, and components associated with Buffer Transistor Transistor

If there is no Red:

(Q710),

and SW 2 Transistor (4712).

(Q711),

SW 1

Inject a signal at If video is present:

Refer to the

If there is no video on the CRT, check for a video waveform at pin 6 of Comb Filter (CM1301).

If video is missing at pm 6 of CM1301:

Check the voltages, waveforms, and components associated with Buffer Transistors (4409,

(IC444),

If video is present at pin 6 of CM1301, check for a video waveform at the emitter of Y Amp Transistor (4305).

If the video is missing:

Check the voltages, waveforms, and components associated with 4305, Buffer Transistor

If the waveform is present at the emitter of 4305:

TP12,

and check for video on the CRT

“IF-AGC”

and CM1301.

section of this

Q410),

(Q416),

Troubleshooting

and AV-Switch IC

and Y Switch IC

guide.

(IC402).

Cheek the voltages, waveforms, and components associated with pin 20 of Y/C/J IC Video Amp Transistor

(Q707,Q7

If there is no Green:

Check the voltages, waveforms, and components associated with pin 22 of Amp Transistor

47 15).

If there is no Blue:

Check the voltages, waveforms, and components associated with pm 24 of Amp Transistor

47 14).

If the raster has a keystone shape:

Check the Deflection Yoke

16).

IC301,

(IC301),

(Q709),

Green Output Transistor

(Q705),

and Green 1K Det Transistors (4706,

Blue Output Transistor

(Q702),

and Blue 1K Det Transistors

Red Output Transistor

and Red 1K Det Transistors

(Q701),

(L550).

(Q704),

(4708).

Video

(4703,

SET 2910 Page 1

TROUBLESHOOTING

If the raster has height or width problems:

Refer to “Vertical”, “Horizontal”, and “Power Supply” sections of this Troubleshooting guide.

AUDIO

Select an

pins 1 and 2 of MTS Decode IC (IC25 1). If there is no audio:

If audio waveforms are present at pins 1 and 2 of IC251, cheek for audio waveforms at pins 1 and 5 of Audio Amp IC (IC405).

If audio waveforms are missing:

If audio waveforms are present at pins 1 and 5 of IC405:

active TV channel and check for an audio waveforms at

Check the voltages, waveforms, and components associated with IC25 1, and pin 10 of IF Module (IF201).

Check the voltages, waveforms, and components associated with Audio Buffer Transistors (4430, Q431), and Buffer Transistors

Check the voltages, waveforms, and components associated with IC405, Audio Mute Transistors Transistor (Q 103).

(4202,Q203).

(4432,

Q433), and Mute

continued

Check the voltages, wavefotms, and components associated

with pins 10 thru 13 of IC2104, Vertical Pulse Transistor

(Q2119), and pins 5 and 36 of Y/C/J IC (IC2103).

If waveform is present at pin 23 of IC2204, check for the proper waveform at pin 61 of IC2204.

If waveform is missing:

Check the voltages, waveforms, and components associated with pins 1 and 2 of IC2 104, and Buffer Transistor

If waveform is present at pin 23 of IC2204:

Check the voltages, waveforms, and components associated

with IC2204.

(43

12)

PIP SYNC

If there is no vertical or horizontal sync:

Check the voltages, waveforms, and components associated with V Buffer 3 Transistor (Q2125), and Buffer Transistor

(42130).

If there is no vertical sync:

Check the voltages, waveforms, and components associated with pm 5 of Y/C/J IC (IC2103).

If there is no horizontal sync:

PIP HORIZONTAL

Check for the proper waveforms at pin 9 of A/D Conv IC (IC2206), and pin 24 of PIP Control IC (IC2204).

If the waveforms are missing:

Check the voltages, waveforms, and components associated with pins 9 of IC2 104, Horizontal Pulse Transistor Out Transistor (4212 (42122).

If waveforms are present, cheek for the proper waveform at pin 60 of

IC2204.

If waveform at pin 60 of IC2204 is missing:

Check the voltages, waveforms, and components associated with Horizontal Width IC (IC2

(Q2117), and pin 39 of Y/C/J IC (IC301).

If waveform at pin 60 of IC2204 is present:

Check the voltages, waveforms, and components associated with IC2204, and IC2206.

4,6

thru 10, and 28 of Y/C/J IC (IC2103), pins 8 and

(42 120),

l),

and Horizontal Drive Transistor

102),

Horizontal Pulse Transistor

Horizontal

PIP VERTICAL

Check for the proper waveform at pin 23 of PIP Cont IC (IC2204). If the waveform is missing:

Check the voltages, waveforms, and components associated with pin 4 of IC2103.

PIP VIDEO

Check for the proper waveform at pin 34 of Y/C/J IC (IC2103). If video is missing at pin 34 of IC2 103:

Cheek the voltages, waveforms, and components associated with V Buffer 1 Transistor (Q2245), V Buffer 2 Transistor

(Q2123), Buffer Transistor (Q413), and AV-SW IC (IC444).

If video is present at pin 34 of IC2103, check for a at pin 16 of A/D Conv IC (IC2206).

If the waveform is missing:

Check the voltages, waveforms, and components associated with Y Out Transistor (Q2139), Y Buffer 2 Transistor Y Amp Transistor pins

14,21,23,25,30,32,33,

If waveform is present at pin 16 of IC2206, check for the proper waveform at pm 4 of Y D/A Conv IC (IC2201).

If the waveform is missing at at pin 4 of IC2201:

Check the voltages, waveforms, and components associated with IC2201, pins

Cheek for the proper waveform at the emitter of YS Buffer Transmitter (42244).

(42

l),

Y Buffer 1 Transistor

of Y/C/J IC (IC2103).

1,46

thru 5 1, and 54 of IC2204.

video

(42 116),

waveform

(Q2102),

and

TROUBLESHOOTING continued

If the wave form is missing at the emitter of

Check the voltages, waveforms, and components associated with 42244, pins 3 thru 6 of IC2 104, and pin 3 1 of IC2204.

If the waveform is present at pin 4 of IC2201:

Check the voltages, waveforms, and components associated with Y Buffer Transistor (42202).

42244:

PIP CHROMA

Check for the waveforms at pins 20 and 22 of\Y/C/J IC (IC2103). If the waveforms are missing:

Check the voltages, waveforms, and components associated with pins 16 thru 22, and 31 of IC2 103.

Check the 3.58MHz oscillator at pins 15 and 18 of IC2103. Check the voltages and components associated with Sub Color

Control and pin 13 of IC2103. Check the voltages and components associated with Sub Hue

Control and pin 12 of IC2103.

If chroma waveform is present at pins 20 and 22 of IC2103, check for the proper waveforms at pins 17 and 18 of A/D Conv IC

(IC2206).

If the waveforms are missing at pins 17 and 18 of IC2206:

Check the voltages, waveforms, and components associated with R-Y Out Transistor (Q2103), and B-Y Out Transistor

(42114).

If the waveforms are present at the proper waveforms at pins 4 of R-Y D/A Conv IC (IC2202), and B-Y D/A Conv IC (IC2203).

If the waveforms am missing at pin 4 of IC2202, and IC2203:

Check the voltages, waveforms, and components associated with IC2202, IC2203, PINP Conv IC (IC2204), and IC2206.

If the waveforms are present at pin 4 of IC2202, and IC2203:

Check the voltages, waveforms, and components associated with R-Y Buffer Transistor (Q2203), B-Y Buffer Transistor

(Q2204), Red Drive Transistor (Q2106), Blue Drive Transistor (Q2107), and Green Drive Transistor (42109).

pins

17 and 18 of IC2206, check for

SET 2910 Page 1

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