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Mitsubishi Electric HITACHI VS-50111 Troubleshooting Manual

Digital ready projection television, v20a chassis, v20c chassis, v20c+ chassis
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Technical Training and
Troubleshooting Guide
Digital Ready
Projection Television
V20A Chassis V20C Chassis
VS-50111
WS-48311
VS-60111
WS-55311
WS-65311
MITSUBISHI ELECTRIC
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
www.mitsubishi-tv.com
T
ECHNICAL
RAINING
2002
V20C+ Chassis
WS-55411
WS-65411
WS-73411

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Summary of Contents for Mitsubishi Electric HITACHI VS-50111

  • Page 1 ECHNICAL RAINING 2002 Technical Training and Troubleshooting Guide Digital Ready Projection Television V20A Chassis V20C Chassis V20C+ Chassis VS-50111 WS-48311 WS-55411 VS-60111 WS-55311 WS-65411 WS-65311 WS-73411 MITSUBISHI ELECTRIC MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC. www.mitsubishi-tv.com...

  • Page 3: Table Of Contents

    V20 Chassis Technical Training and Troubleshooting Guide Table of Contents Introduction ..............................i Chapter 1 -- Chassis Layout & Servicing ....................1-1 Chapter 2 -- Adjustments ........................2-1 Chapter 3 -- Power Supply ........................3-1 Chapter 4 -- Control Circuitry ........................ 4-1 Chapter 5 -- Video/Color Circuitry ......................

  • Page 5: Introduction

    V20 Chassis Technical Training and Troubleshooting Guide Introduction V20A Cha ssis VS-50111 VS-60111 V20C Cha ssis W S-48311 W S-55311 W S-65311 V20C+ Chassis W S-55411 W S-65411 W S-73411 The digital ready V20 chassis is currently available in The V20 chassis is similar in many respects to the V17 three chassis versions, V20A V20C and V20C+.
  • Page 6 V20 Chassis Technical Training and Troubleshooting Guide...

  • Page 7: Chapter 1 -- Chassis Layout & Servicing

    V20 Chassis Technical Training and Troubleshooting Guide Chapter 1 Chassis Layout & Servicing As mentioned in the Introduction, the main differ- Table 1 lists the major circuit functions on board each ence between the V20 chassis and the V17 and V18 PCB.
  • Page 8 V20 Chassis Technical Training and Troubleshooting Guide Figure 2: V20 Chassis-- Main Component Locations Figure 2 maps the Main Component Locations. Also Also note, the FBT and HV Block have been com- visible are the Chassis Locking Clips on the left and bined into a one piece unit.
  • Page 9 V20 Chassis Technical Training and Troubleshooting Guide 2) While holding the lead down, rotate the lead 90º counter clockwise. 1) Push DOWN on the Anode Lead. 3) Carefully remove the Anode Lead from the Flyback Transformer. Figure 4: V20 Chassis -- HV Anode Lead Removal Procedure Note: The front panel buttons must be used, Self Diagnostics NOT those on the Remote Control.
  • Page 10 V20 Chassis Technical Training and Troubleshooting Guide...

  • Page 11: Chapter 2 -- Adjustments

    V20 Chassis Technical Training and Trouble Shooting Guide Chapter 2 Adjustments With the exception of the Service Menu access codes, the general alignment procedures for the V20 chassis remain the same as previous HD ready chassis. For your convenience the following procedures are provided in this chapter: For specific alignments, refer to the Service Manual.
  • Page 12 V20 Chassis Technical Training and Troubleshooting Guide Initial Setup A. Option Menu Setup Follow the steps below for the initial set-up: 1. Select the "MENU" display by pressing the "MENU" button once. 2. Press the number buttons "2", "2", "7", "0" in sequence to select the "OPTION MENU" display. 3.
  • Page 13 V20 Chassis Technical Training and Trouble Shooting Guide Items in the table below are set to following after Initalization. AV Memory Initial Settings Ant-A NTSC COMP. A/V Memory Ant-B 1/2/3 Contrast Brightness Sharpness Color Tint Color Temp. High High High High Video Noise Stnd.
  • Page 14 V20 Chassis Technical Training and Troubleshooting Guide Circuit Adjustment Mode Except for the following, all adjustment items must be performed using the remote hand unit. FUNCTION CHASSIS • Lens Focus • Electrostatic Focus Video Chr A. Activating the Circuit Adjustment Mode 1.
  • Page 15 V20 Chassis Technical Training and Trouble Shooting Guide D. Saving Adjustment Data Press “ENTER” to save adjustment data in memory. The character display turns red for approximately one second in this step. Note: If the circuit adjustment mode is terminated without pressing “ENTER”, changes in adjustment data are not saved.
  • Page 16 V20 Chassis Technical Training and Troubleshooting Guide Use the VIDEO button to select an item. Use the ADJUST buttons to change data. Note: When Item “1 HVOL” is selected the screen goes black except for the data display. This occurs since a black screen is required when making the HV Regulation adjustment. E.
  • Page 17 V20 Chassis Technical Training and Trouble Shooting Guide Cursor Coordinates Specific intersections in the Crosshatch are assigned vertical and horizontal coordinates. These are shown in the preceeding diagram. The Cursor can only be moved to those positions that have coordinates assigned. If the Cursor is at coordinates outside the screen area, the Cursor will not be visible.
  • Page 18 V20 Chassis Technical Training and Troubleshooting Guide Deflection Jungle Menu-2-2-5-7 48" 50"/60" 55" 65" 73" Item# Abbrev. Description Range HD NTSC HD NTSC HD NTSC HD NTSC HD NTSC HWID Width 0~63 HKEY Horiz. Keystone 0~63 EWPT Top EW-PCC 0~63 VHGT Height 0~63 VLIN...
  • Page 19 V20 Chassis Technical Training and Trouble Shooting Guide COARSE CONV GREEN (MENU-2-2-5-9-5) # Abbrev. Description WS-48311 VS-50111 WS-55311 WS-55411 VS-60111 WS-65311 WS-65411 WS-73411 1 HSTA Horiz. Position VSTA Vert. Position 3 SKEW Skew (Y axis) TILT Tilt (X axis) 5 HWID Width HLIN Horiz.
  • Page 20 V20 Chassis Technical Training and Troubleshooting Guide 2-10...
  • Page 21 V20 Chassis Technical Training and Troubleshooting Guide Chapter 3 Power Supplies Regulation in previous models was by Pulse Width As detailed in the Introduction, there are three V20 chas- Modulation (PWM), where the duty cycle of the regu- sis types, V20A, V20C and V20C+. Although differ- lator output was varied to maintain a constant out- ences exist between the chassis types, their Power Sup- put voltage.
  • Page 22 V20 Chassis Technical Training and Troubleshooting Guide • Under normal load conditions, some drive cycles to the MOSFET are dis- abled. Output from the MOSFET is cycled On and Off at approximately a 60 KHZ rate. • If the load is light, even more drive cycles to the MOSFET are disabled.
  • Page 23 V20 Chassis Technical Training and Troubleshooting Guide If the load is heavy, the maximum current level is in- Standby Regulator Circuit creased, supplying more power to the transformer. Figure 3 illustrates a Simplified Version of the Standby Under light load conditions, the current limit is de- Regulator Circuit.
  • Page 24 V20 Chassis Technical Training and Troubleshooting Guide If 9VS supply exceeds the zener point of D9A31, the • On/Off circuitry LED in PC9A50 emits light. The resulting conduction • ACOFF detection circuit of the internal photo transistor decreases the voltage at •...
  • Page 25 V20 Chassis Technical Training and Troubleshooting Guide Switched Supply Regulator When the set is switched On, the P-ON line from the Control Circuit goes High turning Q9A51 On, which: The Switched Supply Regulator is illustrated in Figure • Closes relay K9A50 5.
  • Page 26 V20 Chassis Technical Training and Troubleshooting Guide is rectified by D9A54 and is added to the DC voltage at The 17V supply is the DC source for the Audio Output the collector of Q9A50. IC. In the V20A chassis, audio output wattage is re- duced from 10 Watts to 5 Watts.

  • Page 27: Chapter 4 -- Control Circuitry

    V20 Chassis Technical Training and Troubleshooting Guide Chapter 4 Control Circuitry From the above Block Diagram it is apparent that the Basic Operating Requirements Control Circuitry in the V20 chassis is not radically dif- The µPC basic operating requirements have not changed: ferent from other chassis types.
  • Page 28 V20 Chassis Technical Training and Troubleshooting Guide • A Reset pulse is generated. Two Clock oscillators supply signals to time opera- • The µPC resets to clear the lock up. tions: 1) A 27 MHZ ceramic filter controlled oscillator Input Commands at pins 17 and 18.
  • Page 29 V20 Chassis Technical Training and Troubleshooting Guide This enables the user to control other brand home the- Of course each I C data line has a corresponding clock ater components through the TV, using IR Blasters con- (SCL) line to time data transfer. nected to the IR Output Jacks.
  • Page 30 V20 Chassis Technical Training and Troubleshooting Guide The MN-SDA line controls the bulk of the signal selec- • D-IN transmits data from the PCB-DOUBLER tion and signal processing circuitry in the TV. to the µPC. • SCLK times the data transfer. The C-SDA line, as in previous models, controls the Convergence circuitry V-Chip Control...
  • Page 31 V20 Chassis Technical Training and Troubleshooting Guide Parallel Inputs/Outputs cuitry, IC2V01, is required for the sub picture signal. Of course there are parallel (single purpose) inputs and Sub picture video is applied to pin 7 of IC2V01 and outputs to the µPC. Most of the inputs are status in- sub picture horizontal sync to pin 5.
  • Page 32 V20 Chassis Technical Training and Troubleshooting Guide IC7A00 Microprocessor Outputs PIN# ABBREV. DESCRIPTION DESTINATION CLR KILLER Color Killer (JB-14) IC2M00-79 IC2V00-2 OSD insert timing Transparent gray bckgrnd. IC2V00-2 S480PSYNC Sub Sync Switch Control (JB-6) IC2P00-9&IC2P01-9 (JB-8) IC2P00-10-11 M480PSYNC Main Sync Switch Control SUB CONTRAST Reduces Y amplitude (S-Contr-adj) Q2X31...

  • Page 33: Chapter 5 -- Video/Color Circuitry

    V20 Chassis Technical Training and Troubleshooting Guide Chapter 5 Video/Color Circuitry Two changes in the V20 Video circuitry include an ad- The picture is displayed in either 480p or 1080i scan vanced Digital 3DYC Comb Filter and improved Line format. Improvements in the PCB-DOUBLER, Line Doubler circuitry.
  • Page 34 V20 Chassis Technical Training and Troubleshooting Guide A simplified Block Diagram of the Video/Color cir- • Main and Sub Tuners cuitry is shown. The diagram shows the major circuits, • A PIP Switch IC signal path and interconnections between PCBs. The •...
  • Page 35 V20 Chassis Technical Training and Troubleshooting Guide Although all signals are directed to the DOUBLER cir- PIP insertion occurs in the DOUBLER circuitry and that cuitry, they may not be processed by that circuitry. When signal is selected by the PIP Switch and applied to the the main picture source is either 480p or 1080i, and the VCJ.
  • Page 36 V20 Chassis Technical Training and Troubleshooting Guide it’s respective input signal(s) to the YCbCr format. The IC2M00 is the new advanced digital 3DYC Comb Fil- output of each Decoder is directed to it’s respective ter. In previous models, when the signal source was S- YCbCr Switch IC.
  • Page 37 V20 Chassis Technical Training and Troubleshooting Guide play format and no POP is activated. When PIP is activated the sub picture is inserted in the main picture in IC2Y01. The YS signal from PCB-DOUBLER times the insertion. When the shape or size of the main pic- ture is changed, due to a display format change or POP activation, the main sig- nal 480p and 1080i signals must be pro-...
  • Page 38 V20 Chassis Technical Training and Troubleshooting Guide...
  • Page 39 V20 Chassis Technical Training and Troubleshooting Guide Chapter 6 Deflection & HV Circuitry The above Block Diagram shows the Overall Deflec- Sync Select circuitry selects Main picture sync source. tion and HV circuitry in the V20. The V20 can display The selected output is used to synchronize the Hori- either of two scanning formats, 480p or 1080i.
  • Page 40 V20 Chassis Technical Training and Troubleshooting Guide Sync Signal Path IC2N00 selects 480p/1080i sync from IC2L01, or separate 1080i H and V sync from the DTV inputs. Figure 1 illustrates the Sync Signal Path for both the IC2P01 selects 480p or 1080i sync from IC2N00, or Main and Sub Picture signals.
  • Page 41 V20 Chassis Technical Training and Troubleshooting Guide The Doubler circuit sync pulse outputs are directed to The output from Q5A32 is directed to Q5A31, the the VCJ, IC2V00. Both Horizontal and Vertical Drive Horizontal Output transistor. The output from Q5A31 Generators are in the VCJ.
  • Page 42 V20 Chassis Technical Training and Troubleshooting Guide • Add side pincushion correction, controlled by The H-MUTE line from the µPC and Q5A08 reduce the EWDRV signal from the VCJ. the DC supply during scan frequency change by the • Reduce the Deflection DC supply during same method.
  • Page 43 V20 Chassis Technical Training and Troubleshooting Guide The output of Q5A51 is the drive signal for the Flyback voltage in applied to the inverting input of a second OP- transformer, T5A51. In the Flyback, the signals are Amp in IC5A01. The outputs of both OP-Amps are stepped up and rectified to generate the HV and Focus combined and directed to pin 4 of IC5A00.
  • Page 44 V20 Chassis Technical Training and Troubleshooting Guide X-Ray Protect outputs of all three Op-Amps are tied together at the X-Ray line. X-Ray Protect circuitry is the basically the same as in previous models, as shown in Figure 5. The X-Ray The X-Ray line is normally High.
  • Page 45 V20 Chassis Technical Training and Troubleshooting Guide If X-Ray Protect shuts the TV Off, pressing the Power button will turn the TV back On (it may shut Off again if the problem still exists). If Arc Protect is activated the TV must be switched Off before it can be switched back On.
  • Page 46 V20 Chassis Technical Training and Troubleshooting Guide Error Code Description No error has occurred. X-Ray Protect circuit. Short Protect circuit. Horizontal Deflection failure. Vertical Deflection failure. Table 1: LED Diagnostic Codes Troubleshooting Shut Down The LED flashes the value of the most significant digit (MSD) of the code first, then flashes the value of the Problems.

  • Page 47: Chapter 7 -- Convergence Circuitry

    V20 Chassis Technical Training and Troubleshooting Guide Chapter 7 Convergence Circuitry The above Block Diagram shows that the V20 Con- This is the same basic circuitry used in the last few chas- vergence Circuitry is similar to other models. A sis types.
  • Page 48 V20 Chassis Technical Training and Troubleshooting Guide Correction signals from IC8D00 are converted to ana- • C-ACK … Acknowledgment line, allows log signals in IC8E03 and are then directed to LPF notification to the µPC that a command was and Summing Amplifiers. received.
  • Page 49 V20 Chassis Technical Training and Troubleshooting Guide is directed to the HV Regulation circuitry. DF (Dy- IC8E01 and IC8E02. Each correction signal from namic Focus) is a parabolic signal used by the DBF IC8D00 goes through two stages of amplification: (Dynamic Beam Focus Circuitry).
  • Page 50 V20 Chassis Technical Training and Troubleshooting Guide Convergence Output Circuitry Figure 3 shows the Convergence Output circuitry. This Deflection Yokes. The Convergence Output Circuitry circuitry is basically the same as used in the past. The is shown in Figure 3. It includes pin numbers and com- correction signals are amplified and directed to the Sub ponent nomenclature.

  • Page 51: Chapter 5 -- Sound Circuitry

    V20 Chassis Technical Training and Troubleshooting Guide Chapter 8 Sound Circuitry The above Block Diagram of the Sound circuitry in the • There are no Service Sound Adjustments, these V20 chassis is spread out over three PCBs, PCB-TER- are automatic. MINAL, PCB-SIGNAL and PCB-MAIN.
  • Page 52 V20 Chassis Technical Training and Troubleshooting Guide As in most other models, the user may select either from pins 43 and 45 are directed to Audio Control fixed level, or variable level audio at the Monitor Out- circuitry on PCB-SIGNAL. put Jacks.
  • Page 53 V20 Chassis Technical Training and Troubleshooting Guide Sound Processing Circuitry signals. The TV right and left signal are directed to the AV Switch circuitry on PCB-TERMINAL. Figure 2 shows the Sound Processing and Audio Out- put circuitry. In the V20 chassis, sound processing in- The selected signals from the AV Switch circuit are di- cludes: rected back to IC3A01 at pin 44 and 45.
  • Page 54 V20 Chassis Technical Training and Troubleshooting Guide Audio Output Amplifier Note the DC Supply for IC3E01 is 17 volts for all models except VS-50111 and VS-60111. In these The Audio Output Amplifier, shown in Figure 2, is ba- two models the DC supply is reduced to 12 volts. All sically the same as that in previous models.

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