Sony KV-21FA240 Service Manual ▷ View online
KV-21FA240
KV-21FA240
4
SPECIFICATIONS
1) 1 Vp-p 75 ohms unbalanced, sync negative
2) Y: 1.0 Vp-p, 75 ohms, sync negative; PB: 0.7 Vp-p, 75 ohms;
PR Vp-p, 75 ohms.
3) 500
mVrms (100% modulation), Impedance: 47 kilohms
4) This specifi cation is the maximum wattage.
Design and specifi cations are subject to change without notice.
Manufactured under license from Dolby
Laboratories Licensing Corporation. Dolby
and the double-D symbol are trademarks of
Dolby Laboratories.
Laboratories Licensing Corporation. Dolby
and the double-D symbol are trademarks of
Dolby Laboratories.
As an ENERGY STAR® Partner, Sony
Corporation has determined that this
product meets the ENERGY STAR®
guidelines for energy efficiency. ENERGY
STAR® is a U.S. registered mark.
SRS and the ( )® symbol are trademarks of
SRS Labs, Inc.
Manufactured under license from BBE Sound,
Inc. Licensed by BBE Sound, Inc. under USP
4638258, 5510752 and 5736897. BBE and BBE
symbol are registered trademarks of BBE
Sound, Inc.
Sound, Inc.
WEGA, FD Trinitron and Steady Sound are registered
trademarks of Sony Corporation.
KV-21FA240
Power Requirements
110-220V, 50/60Hz
Number of Inputs/Outputs
Video
1)
2
Y,P
B
, P
R
2)
1
Audio
3)
3
RF
4)
1
Speaker Output (W)
4W x 2, 12W
Power Consumption (W)
In Use (Max)
115W
In Standby (Max)
5)
<1W
Dimensions (W x H x D)
25
1/2
x21x20
7/8
mm
647 x 533 x 530 mm
Mass
62 lbs. 61 oz.
kg
28.4 kg
Television system
PAL-M/PAL-N/NTSC
Channel coverage
VHF: 2-13/UHF: 14-69/CATV: 1-125
Antenna
75-ohm external antenna terminal for VHF/UHF
Picture tube
FD Trinitron
®
tube
Visible screen size
20-inch picture measured diagonally
Actual screen size
21-inch measured diagonally
Supplied Accessories
Remote Commander RM-YA005
Two Size AA (R6) Batteries
Two Size AA (R6) Batteries
KV-21FA240
KV-21FA240
5
WARNINGS AND CAUTIONS
CAUTION
Short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT shield, or carbon painted on the CRT, after
removing the anode.
WARNING!!
An isolation transformer should be used during any service to avoid possible shock hazard, because of live chassis. The chassis of this
receiver is directly connected to the AC power line.
!
SAFETY-RELATED COMPONENT WARNING!!
Components identified by shading and
!
mark on the schematic diagrams, exploded views, and in the parts list are critical for safe
operation. Replace these components with Sony parts whose part numbers appear as shown in this manual or in supplements published
by Sony. Circuit adjustments that are critical for safe operation are identified in this manual. Follow these procedures whenever critical
components are replaced or improper operation is suspected.
KV-21FA240
KV-21FA240
6
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered
connections. Check the entire board surface for solder splashes and
bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that
you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the B+ and HV to see if they are specified values. Make sure
your instruments are accurate; be suspicious of your HV meter if
sets always have low HV.
8. Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described below.
Leakage Test
The AC leakage from any exposed metal part to earth ground and from
all exposed metal parts to any exposed metal part having a return to
chassis, must not exceed 0.5 mA (500 microamperes). Leakage current
can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instructions.
2. A battery-operated AC milliampmeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The “limit” indication is 0.75 V,
so analog meters must have an accurate low voltage scale. The
Simpson’s 250 and Sanwa SH-63TRD are examples of passive
VOMs that are suitable. Nearly all battery-operated digital
multimeters that have a 2 VAC range are suitable (see Figure A).
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate
retaining screw on most AC outlet boxes is also at earth ground. If the
retaining screw is to be used as your earth ground, verify that it is at
ground by measuring the resistance between it and a cold-water pipe
with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble-
light (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on
the line; the lamp should light at normal brilliance if the screw is at
ground potential (see Figure B).
To Exposed Metal
Parts on Set
0.15 µF
1.5 K Ω
AC
Voltmeter
(0.75 V)
Earth Ground
Trouble Light
AC Outlet Box
Ohmmeter
Cold-water Pipe
Figure A. Using an AC voltmeter to check AC leakage.
Figure B. Checking for earth ground.
KV-21FA240
KV-21FA240
7
Detected Symptoms
SELF-DIAGNOSTIC FUNCTION
*One flash count is not used for self-diagnostic.
*If a +B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously. The symptom that is diagnosed first by the mircrocontroller
is displayed on the screen.
**Refer to Screen (G2) Adjustments in Section 2-4. of this manual.
2. Display of STANDBY LED Flash Count
2 times
4 times
5 times
4 times
5 times
LED ON 0.3 sec.
LED OFF 0.3 sec.
LED OFF 0.3 sec.
LED OFF
3 sec.
Standby indicator
3. Stopping the STANDBY LED Indicator Flash
Turn off the power switch on the TV main unit or unplug the power cord from the outlet to stop the STANDBY LED Indicator from flashing.
4. Self-Diagnostic Screen Display
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past
occurrences of failure on the screen for confirmation.
Self Diagnosis
Supported model
The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY LED indicator will automatically begin to flash. The number of
times the LED flashes translates to a probable source of the problem. A definition of the STANDBY LED flash indicators is listed in the instruction manual
for the user’s knowledge and reference. If an error symptom cannot be reproduced, the Remote Commander can be used to review the failure occurrence
data stored in memory to reveal past problems and how often these problems occur.
1. Diagnostic Test Indicators
When an error occurs, the STANDBY LED indicator will flash a set number of times to indicate the possible cause of the problem. If there is more than
one error, the indicator will identify the first of the problem areas.
Results for all of the following diagnostic items are displayed on screen. No error has occurred if the screen displays a “0”.
Power does not turn on
+B overcurrent (OCP)*
V-Protect (OVP)
IK (AKB)
Does not light
2 times *
4 times
5 times
2:0
or
2:1 - 255
4:0
or
4:1 - 255
5:0
or
5:1 - 255
• Power cord is not plugged in.
• Fuse is burned out (F600). (A Board)
• Fuse is burned out (F600). (A Board)
• H.OUT (Q805) is shorted. (A Board)
• IC751 is shorted. (C Board)
• IC751 is shorted. (C Board)
• +13V is not supplied. (A Board)
• IC804 is faulty. (A Board)
• IC804 is faulty. (A Board)
• Video OUT (IC1545) is faulty(A Board)
• IC001 is faulty. (A Board)
• Screen (G2) is improperly adjusted.**
• IC001 is faulty. (A Board)
• Screen (G2) is improperly adjusted.**
No. of Times
STANDBY LED
Indicator Flashes
Diagnostic Item
Description
Self-Diagnositc
Display/
Diagnostic Result
Probable Cause Location
• Power does not come on.
• No power is supplied to the TV.
• AC Power supply is faulty.
• No power is supplied to the TV.
• AC Power supply is faulty.
• Power does not come on.
• Load on power line is shorted.
• Load on power line is shorted.
• Has entered standby state after horizontal raster.
• Vertical deflection pulse is stopped.
• Power line is shorted or power supply is stopped.
• Vertical deflection pulse is stopped.
• Power line is shorted or power supply is stopped.
• No raster is generated.
• CRT Cathode current detection reference pulse
• CRT Cathode current detection reference pulse
output is small.
Power Supply
NG (+5V) for
Video Processor
NG (+5V) for
Video Processor
8 times
8:0
or
8:1 - 255
• IC604 is faulty.
• IC602 is faulty.
• IC602 is faulty.
• No power supply to CRT Anode.
• No RASTER is generated.
• No RASTER is generated.