MITSUBISHI ELECTRIC
2003/2004
™
own
HIGH SPEED TROUBLESHOOTING
V22/V24 & V23 CHASSIS
V22 Chassis
WS-48313 WS-55313 WS-65313
WS-48413 WS-55413 WS-65413
V24 Chassis
WS-48315 WS-55315 WS-65315
V23 Chassis
WS-48513 WS-65513 WS-73513
WS-48613 WS-65613 WS-73713
WS-55513 WS-65713
WS-55613 WS-65813
WS-55813
to
1
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
9351 Jeronimo Road, Irvine, CA 92618-1904
Copyright © 2004 Mitsubishi Digital Electronics America, Inc.
All Rights Reserved
Down To 1 - High Speed Troubleshooting
CONTENTS
INTRODUCTION ..................................................................................................................................................................................... 2
SAFETY PRECAUTIONS ......................................................................................................................................................................... 3
V22/V24 - PWB FUNCTIONS AND LOCATIONS ................................................................................................................................. 4
V23 - PWB FUNCTIONS AND LOCATIONS ......................................................................................................................................... 5
PWB PART NUMBERS ........................................................................................................................................................................... 6
TROUBLESHOOTING CHARTS
V22/V24 & V23 Audio .................................................................................................................................................................. 7
V22/V24 Video/Color ................................................................................................................................................................... 8
V23 Video/Color ........................................................................................................................................................................... 9
V22/V24 & V23 Power ............................................................................................................................................................... 10
V22/V24 & V23 Convergence .................................................................................................................................................... 12
INTRODUCTION
DOWN to 1™ Goal: Isolate the faulty component 9 out of 10 times.
Required tools: Signal Generator such as Sencore VP300 or VP301
DOWN to 1™ High Speed Troubleshooting
The troubleshooting of any PTV chassis involves one of two methods. The first involves an exhaustive checking of all suspect DC and AC voltages,
waveforms, and the like. This is all possible given the necessary time and equipment. The second occurs most frequently in field service, where time is often
insufficient and equipment unavailable or impractical. It is then that all of a technician’s practical experience must be brought to bear in order to make an
educated guess as to where the product failure or difficulty may lie.
This second method is the focus of this publication and the DOWN to 1™ discipline.
Color, Pattern and Perception
Observation is key to an overall evaluation strategy. The details gathered from a precise observation can go a long way toward arriving at a repair solution in
a timely and efficient manner. With this understanding, MDEA has brought the combined technical expertise of its years to bear in creation of the DOWN to
1™ method. For simplicity and easy memorization, color, pattern and perception are employed as the primary tools.
Color
• Each component has its corresponding unique color.
Pattern
• For each troubleshooting case, the component to replace is identified by an oval color pad at the terminating end of its path.
Perception
• A perceived problem provides deductive reasoning clues to its solution.
Main Power Signal Terminal
Doubler
CRT(s) DM
SAFETY PRECAUTIONS
NOTICE: Observe all cautions and safety related notes located inside the receiver cabinet and on the receiver chassis.
WARNING:
1. Operation of this receiver outside the cabinet or with the cover removed presents a shock hazard from the receiver's power supplies.
Work on the receiver should not be attempted by anyone who is not thoroughly familiar with the precautions necessary when working on
high voltage equipment.
2. Do not install, remove or handle the picture tubes in any manner unless shatterproof goggles are worn. People not so equipped should be
kept away while the picture tube is being handled. Keep the picture tube away from the body while handling.
3. When service is required, observe the original lead dress. Extra precaution should be taken to assure correct lead dress in the high voltage
area. Where a short-circuit has occurred, replace those components that indicate evidence of overheating.
X-Radiation warning
The surface of the cathode ray tubes (CRTs) may generate X-Radiation, so take proper precautions when servicing. It is recommended that a lead
apron be used for shielding while handling the CRT. Use this method if possible.
When replacing the CRTs, use only the designated replacement part since it is a critical component with regard to X-Radiation. High voltage must be
set as prescribed in the Service Manual under the section titled Electrical Adjustments.
Leakage current check
Before returning the receiver to the customer, it is recommended that leakage current be measured according to the following methods.
Cold Check - With the AC plug removed, place a jumper across the two AC plug prongs. Connect one lead of an ohm meter to the AC plug
and touch the other lead to each exposed metal part (i.e. antennas, handle bracket, metal cabinet, screw heads, metal overlay, control shafts,
(etc.), particularly any exposed metal part that has a return path to the chassis. The resistance of the exposed metal parts having a return path
to the chassis should be a minimum of 1Mega Ohm. Any resistance below this value indicates an abnormal condition and requires
corrective action.
Hot Check... Use the circuit shown below to perform the hot check test.
1. Keep switch S1 open and connect the receiver to the measuring circuit. Immediately after connection, and with the switching devices of
the receiver in their operating positions, measure the leakage current for both positions of switch S2.
2. Close switch S1, energizing the receiver. Immediately after closing switch S1, and with the switching devices of the receiver in their
operating positions, measure the leakage current for both positions of switch S2. Repeat the current measurements of items 1 and 2 after
the receiver has reached thermal stabilization. The leakage current must not exceed 0.5 milliampere (mA).
V22/V24 Chassis - PCB Functions and Locations
PWB-POWER
PWB-MAIN
PWB-SIGNAL
PWB-TERMINAL
PWB-DOUBLER
Convergence
NTSC Video
Line Double
PWB-Main PWB-Power PWB-Signal PWB-Terminal PWB-Doubler
Horizontal Defl. Power Supplies Control uPC A/V Inputs PIP-POP
Vertical Defl. High Voltage Tuning A/V Selection Picture Format
Audio Amp. SVM VCJ 3D-Y/C 3:2 Pull Down
Convergence Amps.
DBF Generator Decoders 480i to 480p
V23 Chassis - PCB Functions and Locations
PWB-TERMINAL
PWB-DOUBLER
PWB-SIGNAL
PWB-POWER
PWB-MAIN
DM
PCB-Main PCB-Power PCB-Signal PCB-Terminal PCB-Doubler DM
Horizontal Defl. Power Supplies Control uPC A/V Inputs PIP-POP NetCommand
Vertical Defl. Audio Amp. Tuning A/V Selection Picture Format IEEE1394
High Voltage Convergence Amps. VCJ 3D-Y/C Line Double Card Viewer
Convergence NTSC Video 480i to 480p OSD-Menus
Generator Decoders Digital uPC Control
V22/V23 Chassis - PWB Part Numbers
MODEL
PWB-MAIN
PWB-POWER
PWB-SIGNAL
PWB-TERMINAL
PWB-DOUBLER
DM
PWB Part Numbers
WS-48313 930B899003 930B900001 930B901001-48 930B902001 934C063001 WS-48413 930B899003 930B900001 930B901002-48 930B902001 934C063001 WS-55313 930B899003 930B900001 930B901001-55 930B902001 934C063001 -
V22
WS-55413 930B899001 930B900001 930B901002-55 930B902001 934C063001 WS-65313 930B899001 930B900001 930B901001-65 930B902001 934C063001 WS-65413 930B899001 930B900001 930B901002-65 930B902001 934C063001 -
WS-48315 930B899004 930B900002 930B901003-48 930B902001 934C063003 -
V24
WS-55315 930B899004 930B900002 930B901003-55 930B902001 934C063003 WS-65315 930B899005 930B900002 930B901003-65 930B902001 934C063003 -
WS-48513 930B903002 930B904001 930B905001-48 934C060001 934C063001 934C067001
WS-48613 930B903002 930B904001 930B905001-48 934C060001 934C063001 934C067001
WS-55513 930B903002 930B904001 930B905001-55 934C060001 934C063001 934C067001
WS-55613 930B903001 930B904001 930B905001-55 934C060001 934C063001 934C067001
WS-55813 930B903001 930B904001 930B905002-55 934C060002 934C063001 934C067002
V23
WS-65513 930B903001 930B904001 930B905001-65 934C060001 934C063001 934C067001
WS-65613 930B903001 930B904001 930B905001-65 934C060001 934C063001 934C067001
WS-65713 930B903001 930B904002 930B905002-65 934C060002 934C063001 934C067002
WS-65813 930B903004 930B904001 930B905002-65 934C060002 934C063001 934C067002
WS-73513 930B903004 930B904001 930B905001-73 934C060001 934C063001 934C067001
WS-73713 930B903004 930B904002 930B905002-73 934C060002 934C063001 934C067002
V22/V24 & V23 Chassis - Audio Problem
Audio problem
Audio
problem any
or all NTSC
sources
Main
Supply
signal to
antenna
input.
PWB-Main
V22 Chassis
Power Signal Terminal
Check Monitor
Output. Good
YES
audio?
NO
PWB-Power
V23 Chassis
Doubler
Supply
signal to
different
line
inputs
CRT(s)
Have audio
to speakers?
NO
PWB-Terminal
YES
PWB-Signal
V22/V24 Chassis - Video/Color Problem
NO
Is OSD good?PWB-Signal
YES
Supply a
signal and
test each
Input.
PWB-Terminal
Main
YES
Power Signal Terminal
Is any single
Input good?
NO
Doubler
PWB-Doubler
CRT(s)
V23 Chassis - Video/Color Problem
Is OSD good?
NO
Is NTSC
Good?
YES
Make sure DM is
seated on the
PCB-DTV-TUNER.
Also check
connectors
between the PCBSIGNAL and PCB-
DTV-TUNER
PWB-Terminal
YES
Main
YES
Supply a
signal and
test each
Terminal
Input.
Is any single
Input good?
Power Signal Terminal
NO
NO
PWB-Signal
PWB-Doubler
Doubler
CRT(s)
Problem
Corrected?
NO
DM
DM
V22/V24 & V23Chassis - Shut-Down Problem - (Pg 1 of 2)
Shut-Down Problem
While the set is in Shut-Down, press and hold the Front Panel "Device" and "Menu" buttons for five seconds.
Pause
Pause
Observe the flashing pattern of the front panel L.E.D. It will repeat 5 times.
No Fault
Detected
X-Ray
Protect
PWB-Main
V23 Chassis
Main Power Signal Terminal
Set powers up
then shuts down?
Arcing at CRTs
seen or heard?
NO
Doubler
YES
YES
PWB-Power
V22 Chassis
CRT(s)
PWB-Power
CRT(s)
V22/V24 & V23Chassis - Shut-Down Problem - (Pg 2 of 2)
Shut-Down Problem (Continued)
Pause
V23 Chassis Only
Main Power Signal Terminal
Short-Circuit
Protect
Continuous
flashing
Press
RESET
on front
panel.
Doubler
PWB-Power
PWB-Main Pause Deflection
CRT(s)
Problem
Corrected?
DM
NO
Make sure DM is
properly seated on
the PCB-DTV-
TUNER. Also
check connectors
between the PCB-
SIGNAL and PCB-
DTV-TUNER
Problem
Corrected?
NO
DM
V22/V24 & V23 Chassis - Convergence Problem
Enter
Convergence
Adjustment Mode
(MENU-0-3-5-9)
<4> Fine
<5> Coarse
PWB-Signal
YES
Does picture
respond to
adjustments?
NO
PWB-Main
V22 Chassis
PWB-Power
V23 Chassis
Main
Power Signal Terminal
Doubler
CRT(s)
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