Table of Contents
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MITSUBISHI ELECTRIC
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
Projection Television
Technical Training
Chassis
Chassis
VS-45605 • VS-50605 • VS-50705
VS-55705 • VS-60705 • VS-70705
VZ7
VZ7
♦
Features
♦
Alignment Procedures
♦
Circuit Descriptions
♦
Block Diagrams
♦
Troubleshooting Techniques
Models:
www.mitsubishi-tv.com
T
ECHNICAL
RAINING
2000
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Related Manuals for Mitsubishi Electric VS-45605
Summary of Contents for Mitsubishi Electric VS-45605
- Page 1 ECHNICAL RAINING MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC. Projection Television 2000 Technical Training Chassis Chassis ♦ Features ♦ Alignment Procedures ♦ Circuit Descriptions ♦ Block Diagrams ♦ Troubleshooting Techniques Models: VS-45605 • VS-50605 • VS-50705 VS-55705 • VS-60705 • VS-70705 www.mitsubishi-tv.com...
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Page 2: Table Of Contents
VZ7 Chassis Technical Training Table of Contents Section 1 -- Introduction ........................1-1 Latest Technologies .......................... 1-1 User Menus ............................1-2 User Adjustments ..........................1-3 Remote Control ..........................1-4 Front Panel Buttons .......................... 1-5 Diagnostic Mode ..........................1-5 Main Chassis PCB Location ......................1-6 CR Block Connectors ........................ - Page 3 V-Chip Circuitry ..........................6-4 AC OFF............................. 6-5 SHORT Circuit ..........................6-6 X-RAY Protect ..........................6-6 Single Function Inputs/Outputs ......................6-8 Section 7 -- Video/Color Circuitry ....................... 7-1 PIP/POP Feature ..........................7-1 Overall Signal Path..........................7-2 Main/Sub NTSC Decoders ....................... 7-4 PIP/POP Circuitry ..........................
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Page 4: Section 1 -- Introduction
Section 1 Introduction VZ7 Chassis Model/Features FEATURES VS-45605 VS-50605 VS-50705 VS-55705 VS-60705 VS-70705 Chassis VZ7+ VZ7+ VZ7+ VZ7+ Screen Size 45" 50" 50" 55" 60" 70" Optional Optional Included Included Included Included DiamondShield Advanced PIP/POP PIP/POP PIP/POP PIP/POP PIP/POP Digital Convergence... -
Page 5: User Menus
The designations Cr and Cb denote that the R-Y The AV Memory, under Audio Video Settings has and B-Y are reduced in amplitude, R-Y by a factor five AV Memory selections: of 0.71, and B-Y by 0.56. This results in the fol- •... - Page 6 The AGC voltage is used to determine signal strength. creases, both Sharpness and Color adjustments are One of three signal levels can be detected: reduced. • Weak signal -- less than 65 db • Medium signal -- between 65 and 70 db When Auto Picture is ON, the normal adjustment •...
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Page 7: Remote Control
Remote Control The Remote Control for VZ7 models is illustrated in Figure 1-3. Its functions are straightforward. The numerical buttons 0 through 9, are used to enter numerical values for Time Setting, Alarm set- ting, V-Chip Lock Code, etc. The buttons are also used to directly access a channel. -
Page 8: Front Panel Buttons
Figure 1-4: Front Panel Buttons feature. If the duration exceeds 10 seconds, pressing Diagnostic Mode "PIP/POP" terminates the PIP mode. The Diagnostic Mode assists the servicer in isolating the source of a problem, particularly those problems In the Single PIP Insert mode, the "Size" button al- causing the set to switch OFF (shutdown) during nor- lows the user to select the size of the insert picture. -
Page 9: Main Chassis Pcb Location
When the mode is activated, the front panel LED Main Chassis PCB Location starts flashing a two digit code: Figure 1-5 shows the location of the PCBs, and ma- 1) The initial number of flashes denotes the jor components on the main chassis assembly. Two value of the tens digit (MSD) of the code. -
Page 10: Cr Block Connectors
Signal processing circuits are located on the PCB- CR Block Connectors SIGNAL. These include: Care must be taken when connecting the HV leads • Both Tuners to the CR Block. Figure 1-6 illustrates the type of • Video Processing connector used on the CR Block. To disconnect a •... - Page 11 Page 1-8...
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Page 12: Section 2 -- Option Menu And Service Adjustment Mode
Section 2 Option Menu Service Adjustment Mode Option Menu and Service Adjustment items must be set to either a specific setting, data value or set accord- ing to a prescribed adjustment procedure. For specific adjustment instructions, refer to the Service Manual. For training purposes, the Option Menu setup and Service Adjustment procedures are reprinted from the Service Manual. - Page 13 After Initalization, customer controls are set according to the following tables. INITIAL SETTINGS Item Description Initial Setting Item Description Initial Setting Input TV IRIS Receiving Channel 003 CH TV Contrast 100% TV/CATV CATV TV Brightness Recalls previous ch. TV Sharpness Channel Memory All CH (0,0) TV Color...
- Page 14 2. Circuit Adjustment Mode Except for the following, all adjustment items must be performed using the remote hand unit. • Lens Focus • Electrostatic Focus A. Activating the Circuit Adjustment Mode 1. Press the "MENU" button on a remote hand unit. 2.
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Page 15: Option Menu
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. E. -
Page 16: Service Adjustment Mode
Section 3 Convergence Adjustments Convergence Adjustments in the VZ7 chassis are Convergence Mode Description divided into two major categories, Static and Dy- To activate the Convergence Mode, press MENU- namic. The Static Convergence Adjustment has not 1-2-5-9, in sequence. The screen changes to an in- changed. - Page 17 CONV MISC ABBR. DESCRIPTION DATA NOTES HVOL HV DC Control Voltage HV Regulation VINT Interpolation Value (0=NTSC, 1=line db) Preset HINT Horiz. Interpolation Value (0 Req'd) " COUT Conv. IC Output Mode (0=Analog, 1=Digital) " HPLL 1= HPLL Divider Value (256=NTSC) "...
- Page 18 • Horizontal Width, Linearity and Bow. The Fine Adjustment Mode is activated by press- • Vertical Keystone ing (4), when in the Convergence Mode. In this mode • X and Y Axis Tilt the On-screen Data Display changes, and a blinking Cursor appears on the Cross Hatch.
- Page 19 DF (Dynamic Focus) ABBR. DESCRIPTION RANGE DATA NOTES Dynamic Focus - Horiz. ±511 -300 Preset Dynamic Focus - Vertical ±511 -159 " Table 3-5 Although not shown on the screen, horizontal and The following describes the effect of Fine Adjust- vertical coordinates are assigned to the Cross Hatch ments in more detail.
- Page 20 side the picture area (off the screen). If the Cursor is tal cross hatch lines at the sides of the screen. The located at these coordinates it will not be visible, and same is true for vertical coordinate 8. Adjusting hori- must be moved to the visible area of the screen, us- zontal position effects the vertical crosshatch lines ing the ADJUST buttons.
- Page 21 Moving the Cursor Adjusting Data The Cursor is moved using the ADJUST buttons. Pressing ENTER toggles the Cursor from the Move The Cursor only stops at intersections that are as- to the Adjust Mode, the Cursor stops flashing. The signed horizontal and vertical coordinates. intersection at the Cursor, can be adjusted vertically •...
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Page 22: Fine Adjustment Mode
Pressing the AUDIO button toggles the color from GREEN to RED to BLUE, and back to GREEN. In the RED and BLUE modes all three colors are dis- played. However, only Red can be adjusted in the RED mode, and only Blue in the BLUE mode. -
Page 23: General Adjustment Procedure
current horizontal coordinate position. In Figure 3- Convergence Adjustment touch up. However, it must 5, vertical coordinate 3 and horizontal coordinate 6 be remembered that it may also be due to: are shown. Horizontal coordinates range from 0 to 1) Incorrect preset data value in the CONV- 8, and the vertical ranges from 0 to 9. - Page 24 The following General Procedure sequence serves 3) Static Convergence -- if too far off, correction as a reference. It is not meant to be performed each may be out of the range of the Convergence cir- time the set is serviced. However, if a quick touch cuitry.
- Page 25 Page 3-10...
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Page 26: Section 4 -- Convergence Circuitry
Section 4 Convergence Circuitry Overall Convergence Circuitry The Convergence Correction Circuitry in the VZ7 chassis is digital. Figure 4-1 illustrates a Basic Block Figure 4-2 shows a simplified diagram of the Over- Diagram of the circuit. Horizontal and vertical pulses all Convergence Circuitry. - Page 27 Page 4-2...
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Page 28: Dac & Lpf Circuitry
The signals from IC800 are directed to Digital to DAC & LPF Circuitry Analog Converters in IC8E01, IC8E02 and IC8E03. Figure 4-3 illustrates the circuitry of one Digital/Ana- Each of the ICs is comprised of two separate Digital log Converter IC, and its associated LPF circuitry. to Analog Converters. -
Page 29: Amplifier/Summing Circuitry
of the analog signals, and directs them to Amplifier/Summing circuits located in the second stage of the same ICs. Amplifier/Summing Circuitry Figure 4-4 illustrates the Horizontal Cor- rection Amplifier/Summing circuitry. The Vertical Correction circuitry is the same except for component notation. The Am- plifier/Summing circuitry is within the sec- ond stage of the ICs used in the LPF. - Page 30 The circuitry related to Q5A01 thru Q5A06 is a Dy- of the Dynamic Regulator is routed through resis- namic Regulator. It compensates for width changes tive networks to the (+) input of Horizontal Correc- due to changes in the HV circuit load. The capaci- tion Output Amplifier.
- Page 31 Page 4-6...
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Page 32: Convergence Control Circuitry
Convergence Control Circuitry PLL circuitry in IC809 generates timing signals for the operation of IC800, and the generation of the Figure 4-6 illustrates the Convergence Control Cir- internal Crosshatch pattern. The PLL is phase locked cuitry. The Main Control Microprocessor, IC700, to horizontal sync, input to IC809 at pin 4. - Page 33 Page 4-8...
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Page 34: Section 5 -- Power Supply
Section 5 Power Supply... -
Page 35: Switch Mode Regulator
Switch Mode Regulator Self Generated DC Supply Over Voltage Protect Regulation Feedback Start Up Voltage... -
Page 36: On/Off Circuitry
Over Current Protection ON/OFF Circuitry Set ON Operation Figure 5-2 Set OFF Operation Figure 2... -
Page 37: Deflection/Hv Generated Supplies
Deflection/HV Generated Switched Supplies Figure 5-3... - Page 38 Power Distribution Figure 5-4...
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Page 39: Troubleshooting
Troubleshooting Before replacing the IC try resetting it an Isolation Transformer must be used Figure 5-5 Excessive load... -
Page 40: Section 6 -- Control Circuitry
Section 6 Control Circuitry Control Circuity remote. Most output commands are communicated by way of four I C Buses. Even with many advanced features such as Digital Convergence Circuitry, PIP/POP, V-Chip Program Besides receiving and generating commands, the in- Blocking and the Diagnostic Mode, the Control cir- ternal circuitry in the µPC: cuitry is not overly complex. -
Page 41: Input Commands
Basic Operating Requirements The basic operating requirements for the µPC are typical. They are listed below and illus- trated in Figure 6-1. • A DC Power Supply • Ground returns • A Clock signal to time all operations. • Reset circuit to set the µPC to its nominal starting point. -
Page 42: Overall Control Circuitry
Overall Control Circuitry the controlled circuits shown in Figure 3 are con- The µPC controls the TV’s circuitry mainly through ventional and need no explanation: three I C data lines, as illustrated in Figure 6-3. Two • IC2Y02 … DAC of the I C lines are dedicated to a specific function: •... -
Page 43: V-Chip Circuitry
V-Chip Circuitry To monitor the sub picture source, the sub picture Figure 6-4 shows the V-Chip circuitry in the VZ7 signal is buffered by Q6C31 and directed over two chassis. Main picture Composite Video is input to paths: pin 100 of the Main µPC. The internal circuitry uses •... -
Page 44: Ac Off
Protection and Status Inputs ter of Q7A20, through R7A11, and zener diode The inputs at pin 20, 46 and 47, as shown in Fig- D7A20. Since Q7A20 is an NPN transistor, and the ure 6-5, are protection and status inputs, informing base is tied to ground, the transistor conducts. -
Page 45: Short Circuit
X-RAY Protect Figure 6-8 illustrates the X- RAY Protect circuitry. The logic at pin 47 of the uPC is controlled by two protect cir- cuits, monitoring for excess HV and Beam Current. To monitor HV, a sample of the HV is derived from the resistive divider in the CR Block, and is directed to pin 5 of IC501. - Page 46 Arc Protect base of Q523 LOW. When Q523 conducts it turns The Arc Protect circuit is also shown in Figure 6-8. the set OFF by pulling the P-ON command to the It does not control the logic at the X-RAY input to power supply LOW.
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Page 47: Single Function Inputs/Outputs
Single Function µPC Inputs/Outputs The outputs used to perform specific functions, such There are, of course, µPC inputs and outputs that as TV On/Off, Sound Mute, Antenna Input selec- serve specific purposes. The inputs are basically Sta- tion, etc., are listed in Table 6-2. tus Inputs, informing the µPC of the TV’s current operating status. - Page 48 Section 8 Deflection Circuitry of key points for that circuit. The simplified dia- From the above block diagram it is apparent that the grams are listed below: Deflection circuitry in the VZ7 is similar to many • Figure 8-1: Deflect Drive Generator other designs.
- Page 49 Deflection Drive Generator Key Points • The VCJ generates both Horizontal and Vertical Drive signals. • Both the Vertical and Horizontal Drive signal are derived by dividing the output of the 32 x FH (503.4 kHz) VCO. • If the Horizontal Pulse fed back from the FBT to pin 43 of the VCJ is missing, the CRTs are auto- matically blanked by the VCJ.
- Page 50 Horizontal Deflection and HV Key Points • The Horizontal Drive from the VCJ drives both the Horizontal and HV Outputs. • The saturable reactor transform, T501, is controlled by the HV Regulation circuit. • The FBT generates the HV, Focus, 230V, 34V, and CRT filament supplies. •...
- Page 51 HV Regulation Key Points • The sample of the HV from the CR Block is amplified and applied to the inverting input of the OP Amp at pin 9 of IC501. • The HV Adjustment voltage from the Convergence circuity is amplified and applied to the non inverting input of the OP Amplifier, at pin 10 of IC501.
- Page 52 Scan Velocity Modulation Key Points • The input signal is a differentiated video signal from the VCJ. • The signal is amplified and applied to the three SVM coils. • The signal either aids the horizontal deflection signal (increasing horizontal scanning velocity), or bucks the deflection signal (decreasing scanning velocity).
- Page 53 Dynamic Beam Formation Key Points • The DBF circuitry improves edge focus. • A parabolic waveform from the Convergence Waveform Generator is amplified and added to the focus voltage in the Focus VR Block. • The DC Supply for the DBF Output stage, Q5K00, is derived by rectifying the large pulses from the Horizontal Output transistor.
- Page 54 Vertical Output Key Points • IC451 amplifies the V-Drive signal from the VCJ and directs it to the vertical windings in the three Deflection Yokes. • The charge on C451 provides additional DC for the Vertical Output stage during vertical retrace. •...
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- Page 56 Section 7 Video/Color & PIP/POP Circuitry VZ7+ VS-45605 VS-50705 VS-60705 VS-50605 VS-55705 VS-70705 Increased PIP functions in the VZ7+ chassis models In all of the PIP/POP modes, pressing the “PIP/ makes a more complex Video/Color signal path. The POP” button after 10 seconds terminates the PIP above illustration shows the PIP (Picture In Picture) mode.
- Page 57 Page 7-2...
- Page 58 Overall Video/Color Signal Path The sub picture video signal from IC2K01 is applied to an NTSC Decoder in IC6C02. The sub picture The simplified diagram in Figure 7-1 shows the main YUV output signals are also applied to IC6P01. ICs in the signal path. Discrete component buffers, amplifiers, etc.
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Page 59: Main/Sub Ntsc Decoders
Main/Sub NTSC Decoders Figure 7-2 shows a more detailed diagram of the NTSC Decoder cir- cuits. In the Main NTSC De- coder, IC6C01, (VZ7+ only) the internal switches select the path of the Main Y and C signals. The Main-Y signal passes through Delay circuitry, is amplified and then output from the IC. - Page 60 The signals are then converted back to analog and in the sequence required to produce the signal for output at the YUV outputs of the IC. the Side by Side pictures. The signals are converted back to analog and directed out the YUV outputs of The PIP-Y signal is applied directly to pin 7 of the the IC.
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Page 61: Vcj Video/Color Internal Path
Control and Timing In the POP mode (VZ7+ only), the combined main The operation of the PIP/POP circuitry in IC6P01 is and sub picture Y signals are input to the VCJ at pin controlled by the MAIN-SDA line from the Control 63. - Page 62 Matrix and RGB Circuitry The YS Switch, inserts On Screen Display (OSD) The R-Y and B-Y signals from the YUV Switch pass information into the Main Signals. OSD signals are through Axis circuitry. The circuit sets the axis of applied to pins 14, 15 and 16. The YS signal at pin the R-Y and B-Y signals and generates the G-Y sig- 13 times the insertion of the OSD.
- Page 63 at pin 1, 2, 3, 4, 6 and 7 determine at what point, and The Cutoff circuitry sets the point at which each how much blue signal amplitude is increased. The CRT starts to conduct. These are set when perform- DC voltages are derived from resistive dividers and ing CRT Cutoff Bias adjustments.
- Page 64 This circuitry is also used for CRT Protection, against loss of deflection, and by the Spot Killer circuit. Horizontal pulses are applied to the base of Q522, and a Vertical Sawtooth from the Vertical Yokes ground return circuit is applied to base of Q401. The conduction of the two tran- sistors holds their collector voltages below the zener...
- Page 65 RGB Output Amps & AKB AKB Circuitry The AKB circuitry automatically adjusts the CRTs The RGB Output Amplifier circuitry on all three Cutoff Bias point if CRT characteristics change with PCB-CRTs is the same, except for component no- age. To detect a change in CRT characteristics, the menclature.
- Page 66 During the VBI, all three CRTs are cutoff by the blank- ing pulse. The AKB pulse drives the CRT to conduction. At the point of conduction the Current Detector, Q6G1, con- ducts. The resulting pulse from Q6G1 is applied to the base of Q6G3.
- Page 67 On-Screen-Display Signal Path The Red, Green and Blue signals output from the two sources are combined within the OR gates in- On-Screen Displays inserted into the main picture ternal to IC703 to form the RGB signals applied to by the VCJ, IC2V00, can be sourced from two dif- the VCJ.
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Page 68: Section 9 -- Audio Circuitry
Section 9 Audio Circuitry Overall Audio Signal Path The outputs at pin 6, and pin 47 of IC3A01, are di- rected over two paths: The Audio Signal Path in the VZ7 chassis is shown 1) To the Power Amplifiers in IC301, and then in Figure 9-1. - Page 69 Page 9-2...