Mitsubishi Electric WL-82913 User manual

MITSUBISHI ELECTRIC
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
9351 Jeronimo Road, Irvine, CA 92618-1904
Copyright © 2004 Mitsubishi Digital Electronics America, Inc.
All Rights Reserved
™
Down to1
2004
HIGH SPEED TROUBLESHOOTING
V23L CHASSIS
V23L Chassis
WL-82913

1
DownTo1-HighSpeedTroubleshooting
CONTENTS
INTRODUCTION ....................................................................................................................................................................................... 2
SAFETYPRECAUTIONS .......................................................................................................................................................................... 3
V23L-PWBPARTNUMBERS,FUNCTIONSANDLOCATIONS .......................................................................................................... 4
TROUBLESHOOTINGCHARTS
V23LAudio ..................................................................................................................................................................................... 5
V23L Video/Color ........................................................................................................................................................................... 6
V23LFrontPanelIndicators .......................................................................................................................................................... 7
V23L ShutDown /Self Diagnostics ............................................................................................................................................... 8

2
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

3
SAFETYPRECAUTIONS
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. 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.
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).

4
V23LChassis -PCB PartNumbers,Functions andLocations
PWB-TERMINAL
PWB-FORMATTER PWB-SIGNAL
PWB-POWER
PWB-SUB-POWER
DM
PWB-SUB-POWER PWB-POWER PWB-SIGNAL PWB-TERMINAL PWB-FORMATTER DM
930B913001 930B906001 930B905008 934C060008 930B908001 934C067004
Lamp Power SupplyStandby Power SupplyControl uPC A/V Inputs PIP-POP NetCommand
Main Power SupplyNTSC Tuning A/V Selection Picture Format IEEE1394
3D-Y/C Scalar to 1080P Card Viewer
NTSC Video OSD-Menus
Decoders Digital uPC Control

5
V23LChassis -Audio Problem
Audio problem Audio
problem any
or all NTSC
sources
Supply
signal to
different
line
inputs
YES
NO
Supply
signal to
antenna
input.
Have audio
to speakers?
PWB-Signal
PWB-Terminal
NO
YES
Check Monitor
Output. Good
audio?
Sub-Power Power Signal Terminal Formatter
PWB-Power
DM

6
V23Chassis -Video/ColorProblem
Supplying 480i,
480p and 1080i
formatted
signals, test
each Terminal
Input.
Is any single
Input good? PWB-Formatter
YES
PWB-Terminal
Is OSD good?
PWB-Signal
NO
YES
NO
Sub-Power Power Signal Terminal Formatter
Is NTSC
Good?
NO
DM
YES
DM
Make sure DM is
seated on the
PCB-DTV-TUNER.
Also check
connectors
between the PCB-
SIGNAL and PCB-
DTV-TUNER
Problem
Corrected?
NO

7
V23LChassis -Front PanelLED Indicators
POWER/TIMER LAMP STATUS
Off Off Off Power Off Normal
Green Off Off Power ON Normal
Slow Blinkin
g
Green Off Off Timer is set to turn TV On Normal
Fast Blinking Green
for 1 Minute Off Off Starting Up After AC Loss or
Power On in Low Energy Mode Normal - DM Boot Sequence
Off Off Blinking
Yellow Lamp Cooling after Power Off Normal - Wait For Cooling Before Power
On
Fast Blinking Green -
Never Stops Off Off Abnormal DM Boot Sequence
Make sure DM is properly seated on the
PCB-DTV-TUNER. Also check
connectors between the PCB-SIGNAL
and PCB-DTV-TUNER
Off Off Yellow Temperature High Allow to cool. Clean Filter. Check
Ventilation. Perform Self Dia
g
nostics.
Off or Green Yellow Off Lamp Usage > 3000 Hrs Normal - Near Future Lamp Failure
Warnin
g
Off Blinking
Yellow Off Lamp Cover Open Perform Self Diagnostics
Off Blinking
Yellow Off No Lamp Perform Self Diagnostics
Off Red Off Lam
p
Failure Perform Self Dia
g
nostics
Off Off Red Fan Sto
p
Perform Self Dia
g
nostics
Off Off Red Circuit Failure Perform Self Dia
g
nostics
FRONT PANEL LED INDICATIORS
LED INDICATOR CONDITION CORRECTIVE ACTION

8
V23LChassis -Shut-Down Problems /Self Diagnostics
Error Code Probable Cause Corrective Action
Pause 12 No error detected Check Power Supply
Pause 22 Recovery from
momentry Reset Perform System Reset
Pause 31 Lamp not detected Install/Re-seat Lamp
Pause 32 Lamp Cover open Install/Reseat Lamp Cover
Pause 34 Lamp abnormality Replace Lamp
Pause 35 Fan failed Check Fans and Connections
Pause 38 Excess Lamp
Temperature Check Fan & Sensor Connections
Pause 39 Excess LCOS
Temperature Check Fan & Sensor Connections
Pause 41 Short Detected Check Power Supply
Pause 42 Excess PCS
Temperature Check Fan & Sensor Connections
Pause 43 Driver Temperature
or Voltage abnormal Check Fan & Sensor Connections
SELF DIAGNOSTICS
On Front Panel, Press and Hold the "DEVICE" and "MENU" buttons for 5 Seconds
LED Blinking
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