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Related Manuals for THOMSON ITC222
Summary of Contents for THOMSON ITC222
- Page 1 VERTICAL RED BIAS <21-B> TP24 RED OUTPUT TP50 194V E5003 E5007 GRN BIAS TECHNICAL TRAINING ITC222 & G ONVERGENCE EOMETRY...
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Page 3: Foreword
GRN BIAS FOREWORD This publication is intended to aid the technician in servicing the ITC222 television chassis and is directed at convergence and geometry procedures Although some theory is involved, the manual concentrates on correct adjustment and alignment of geometry and convergence after an SSB module replacement or after other repairs that may require full or partial geometry or convergence alignment. -
Page 4: Publication Overview
UBLICATION VERVIEW This publication is intended to detail procedures for returning the convergence of an ITC222 instrument to manufacturing specifications and assuring the performance of Autoconvergence. Procedures to do so begin the manual. Informational and tutorial sections are included only as Appendix items. -
Page 5: Table Of Contents
Contents FOREWORD ............................3 .......................... 4 UBLICATION VERVIEW ............................6 NTRODUCTION CRT R ..........................7 EPLACEMENT SSB M ........................7 ODULE EPLACEMENT .......................... 8 ONSUMER OMPLAINTS ........................9 UTOCONVERGENCE AILURE ........................11 ONVERGENCE ATTERN Geometry ..................12 ......................14 ENTERING DJUSTMENT ......................... -
Page 6: Introduction
NTRODUCTION Geometry and convergence for the ITC222 are more interactive than previous chassis designs. If geometry is not correct or too far from nominal settings, even though geometry and convergence both look acceptable, autoconvergence may not operate. While it may be tempting for the technician to return the set to the consumer with both agreeing autoconvergence will not work, it is not a recommended or endorsed completion to a repair. -
Page 7: Crt Replacement
Only then should the remainder of the geometry alignments be done. Once geometry is completed may convergence be done. There are also instructions in the event the original alignments are not available. ITC222 Geometry & Convergence Procedures... -
Page 8: Consumer Complaints
This is the most difficult scenario as the points cannot be seen. The failure location and careful observance of the screen may provide a clue as to where the pattern is off. For example, in the next screen, ITC222 Geometry & Convergence Procedures... -
Page 9: Autoconvergence Failure
Sensor Calibration and Autoconvergence. When autoconvergence fails the most recent successful autoconvergence alignment values are placed back into the registers. So if autoconvergence fails during sensor calibration but convergence is otherwise very close or even ITC222 Geometry & Convergence Procedures... - Page 10 D, Field Service Menu to determine how to identify the color and area convergence stops on and work on that specific area. The ITC222 service adjustments are forgiving. In most cases it is not necessary to store adjustments immediately!!! The service menu will remember the values before adjustments began allowing the return to previous alignment values if necessary.
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Page 11: Convergence Pattern
The object of any convergence procedure is to return convergence to the out of box alignment condition. A properly converged pattern will appear similar to the following picture of an ITC222 instrument at the end of the production facility. (Some enhancement has been done to highlight the onscreen pattern.) The display represents a properly convergence instrument and how it should... -
Page 12: Geometry
Alternately the component inputs may be used for the 2.14H pattern input and either the baseband or RF inputs used for 2H. NOTE: As with other Thomson chassis, the service menu will make adjustments on the scan rate that is currently onscreen. In other words if the onscreen display is 2H, when the service mode is entered all adjustments will be performed in the 2H mode. - Page 13 If a CRT or main yoke has been replaced continue to the Centering Ring Adjustments. Otherwise skip to the “Horizontal Position” setup. ITC222 Geometry & Convergence Procedures...
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Page 14: Centering Ring Adjustment
Green or the Blue crosshair such that the center vertical line is to the right of the Green. Use the following table to determine how far right or left the lines should be. ITC222 Geometry & Convergence Procedures... - Page 15 Neither Vertical Slope, Horizontal Position or the centering rings should be adjusted again regardless of other changes to convergence or geometry!!! Horizontal Position may require additional alignment but only after all other convergence and geometry alignments are completed. ITC222 Geometry & Convergence Procedures...
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Page 16: Geometry Alignment
Geometry alignment, while not being critical must be reasonably close to the final convergence pattern. The two main purposes of geometry alignment in the ITC222 are to assure the convergence amplifiers are not overworked and to provide a reference for the sensor calibration routine. - Page 17 The following illustrations demonstrate the effect of each geometry adjustment on the raster. Keep in mind the proper way to adjust geometry in the ITC222 is to make small adjustments using a test pattern with known centerlines and outer boundaries, but always doing critical observance by returning to the internal convergence pattern.
- Page 18 Adjusts the raster width. Refer to the example screen. The outermost pattern lines should be about 1/2” from the frame. If the raster cannot be perfectly centered it should always be closer to the left than the right. Horizontal Amplitude ITC222 Geometry & Convergence Procedures...
- Page 19 Adjusts the EW tilt of the raster. Adjust for raster appearance closest to the template. EW Trap EW-Symmetry Adjusts the right/left sides to be equal in tilt. Adjust for raster appearance closest to the example. EW Symmetry ITC222 Geometry & Convergence Procedures...
- Page 20 H Parallel Breathing Adjusts the effect of beam current on raster size. If excessive breathing is noted when switching from dark to light scenes, make adjustments two steps at a time until breathing is minimized. ITC222 Geometry & Convergence Procedures...
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Page 21: Geometry Templates
Of course the second pattern will not instantly appear when the convergence yokes are reconnected. It is the result of both correct geometry and convergence alignments. EOMETRY EMPLATE WITHOUT ONVERGENCE EOMETRY EMPLATE WITH ONVERGENCE ITC222 Geometry & Convergence Procedures... -
Page 22: Convergence
The “Clear” button takes the alignment back one screen returning the technician to the previous service screen. “OK” initiates the highlighted command in the text screens, and toggles the alignment color in the alignment screens. ITC222 Geometry & Convergence Procedures... -
Page 23: Convergence Template Design
There are two types of templates available for reconverging the ITC222 instrument line; mylar and string. Part number MTITC222 contains individual mylar templates for the four common screen sizes, 40”, 52”, 56”... -
Page 24: String Calculations
The formula is the same for all screen sizes and is a constant ratio of screen width to screen height. The following table shows the measurements for the 40”, 52”, 56” and 61” screen sizes. Any ITC222 Geometry & Convergence Procedures... -
Page 25: Level 2 Convergence Alignment
ITC222 may be calculated using the previous formula. 40": 16" 40": 8" 40": 17 9/16" 40": 8" 40": 16" 52": 21" 52": 10 5/8" 52": 22 11/16" 52": 10 5/8" 52": 21" 56": 22 1/4"... -
Page 26: Level 3 Convergence Alignment
Move Centering Rings in Direction of Distortion The amplifier has reached maximum deflection current causing the distinct plateau effect. The proper adjustment location will probably never be reached however the flattened pattern may provide ITC222 Geometry & Convergence Procedures... - Page 27 The same is true if patterns are flat either side of the horizontal center line. If they point to each other, vertical size is too tall. If they point away from the center line vertical size is too narrow. ITC222 Geometry & Convergence Procedures...
- Page 28 If a technician converges an instrument but forgets to store it into EEPROM, the next time power is removed or the consumer accesses and runs autoconvergence, convergence will return to its state prior to the technician alignment efforts. ITC222 Geometry & Convergence Procedures...
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Page 29: Hints & Tricks
Then collapse geometry and proceed to Level 3, straighten out the wraparound, return geometry to its original settings, then continue with convergence adjustment using only Level 3. ITC222 Geometry & Convergence Procedures... - Page 30 Return to the second hump and correct it fully, then correct the third. This “walking” method of ironing out humps such as this may be used at any opportunity. ITC222 Geometry & Convergence Procedures...
- Page 31 All 52 may be moved in the horizontal and vertical directions the same as the onscreen alignment points. Use the points wisely. If they are too far from the correct locations, sensor calibration and thus autoconvergence will fail. Begin in Center Moving Outward Clockwise ITC222 Geometry & Convergence Procedures...
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Page 32: Appendix A, Chipper Check
Appendix A Chipper Check & the ITC222 Chipper Check performs one extremely important function in the ITC222 chassis line. It has the ability to download critical geometry and convergence information and alignment data from one SSB module and transfer them to another without affecting SSB related adjustments such as tuner, IF and audio alignments. -
Page 33: Ssb Module Replacement
Chipper Check will be used instead of one from the original SSB. NOTE: It is always a good idea to store the original alignments for any ITC222 SSB module before beginning procedures that may change those alignments. In the event of catastrophic errors due to manipulation of EEPROM data, the original file may always be used to put the module back to its original condition. - Page 34 TECI connection on the SSB module. Then launch Chipper Check and enter the “Dead Set” mode. Select the ITC222. 3. Follow the on screen instructions to establish a Chipper Check connection with the chassis.
- Page 35 14. Select “Bus Quiet” by holding down the “OK” button for >2.5 seconds to place the set in Chipper Check Mode. 15. Now start Chipper Check and highlight the ITC222 under “Select Chassis” on the main menu. 16. Follow the on screen instructions to establish a Chipper Check connection with the chassis.
- Page 36 The Geometry files are uploaded from the main EEPROM to the current mode RAM immediately when the instrument is turned on. However the ITC222 uses the convergence values from the current mode EEPROM, not the default. The uploaded convergence files remain in the default convergence EEPROM until manually moved.
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Page 37: Ot Be
5. With the PC and CC interface box already connected and running, first connect the interface box to the chassis via the TECI connection on the SSB module. Then launch Chipper Check and enter the “Dead Set” mode. Select the ITC222. 6. Follow the on screen instructions to establish a Chipper Check connection with the chassis. -
Page 38: Appendix B, Field Service Menu
IELD ERVICE The Field Service Menu screens are used for most adjustments and alignments in the ITC222. Generally there are two types of screens; Text and Alignment. The Text screens provide information on the menus and for specific alignments and appear similar... -
Page 39: Field Service Mode Remote Control Button Functions
UTTON UNCTIONS The graphic shows only a portion of the remote used for the ITC222. There are several versions of this remote however the button functions will remain the same regardless of where they are located on the remote. The field service remote control commands are also universal across most RCA and RCA Scenium CRK76 style remotes so the original remote is not necessarily required. - Page 40 Other remote control button functions are: CLEAR/Exit: Exits the current alignment menu and returns to the previous service menu. Additionally when in the main service menu removes the service menu and displays active video full screen. MENU: Not active when in the Field Service Menu. When the FSM has been removed by pressing CLEAR, pressing and holding the MENU button for about 8 seconds returns to the FSM from active video at the same point it was exited.
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Page 41: Convergence Error Codes
ONVERGENCE RROR ODES There are a number of error codes linked with specific convergence failures. Remember that “Sensor Calibration” and “Autoconvergence” are two separate functions of convergence. Sensor Calibration is done in two parts. Setting luma levels is done with convergence essentially “zeroed” such that it has little effect on the sensor calibration routine at that point. -
Page 42: Event History
EVENT HISTORY Return Clear Event Codes Time Stamp Code Count Unit 0135:30 0090:10 0043:54 0001:20 0000:00 Test: Brightness Sensor: 2 Color: R Scan Mode: 2H DOWN < > SELECT/CHANGE VENT ISTORY The Event History is where all errors are stored and available to the technician. There is a specific section for the Sensor Calibration errors. - Page 43 down. Return the vertical size to its original setting and move vertical position up a few notches. In this manner geometry can be dialed in reliably. The most difficult failures are the corners. In those locations it is difficult to determine whether horizontal or vertical size is at fault.
- Page 44 changes. The technician has the only possibility to change the original EEPROM Sensor Calibration and Convergence coordinates by storing any new coordinates into the default EEPROM using “Defaults” in the Autoconvergence menu. Default Sensor Calibration locations and Convergence points stored at the time of manufacture Store 2H EEPROM...
- Page 45 NDERSTANDING THE ONVERGENCE As with previous chassis, many steps are required after manual convergence to make certain the instrument will successfully restore the instrument to acceptable convergence over time. The convergence service menu is used for these steps. The main convergence menu appears below. CONVERGENCE ALIGNMENT Return Level 1 (3x3)
- Page 46 CONVERGENCE ALIGNMENT Return To keep the stored convergence correction for Autoconvergence, you must "Store Defaults" by holding the "OK" button for about 2.5 seconds then perform "Sensor Calibration" Store Defauts Sensor Calibration DOWN < > SELECT/CHANGE When the “Default” menu selection is chosen the next screen appears. Since sensor calibration has been previously successful, the check mark will remain.
- Page 47 Pressing “Default Red/Green/Blue” will return all three colors to the values held in the factory default EEPROM. If only one or two colors need to be returned to that state, select the one or ones desired. “Store Defaults” is essentially the same procedure as the “Store Defaults” function in the “Store” routine except it is not required to do another “Sensor Calibration”.
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Page 48: Appendix C, Screen Dimensions & Mylar Pattern
CREEN IMENSIONS The following chart contains the physical dimensions for the most common Thomson instrument screen sizes. The conversion is from the typical diagonal size to an X, Y measurement. Frame dimensions may change over different cabinet styles so it is a good idea to measure the full height and width on each instrument assuring the centerline is as accurate as possible. -
Page 49: Appendix D, Decimal To Fraction Conversion Table
Appendix D Decimal to Fraction Conversion EASUREMENT ONVERSION HART The following conversion chart converts decimals to carpentry dimensions useful when using the string dimension formulas. The convergence pattern easily tolerates variations up to about 5% which equates to about +1/16”. Therefore using the nearest 16th inch measurement is adequate. -
Page 50: Summary
This manual has attempted to cover all aspects of the convergence and geometry alignments required for the ITC222 chassis series. It provides the correct procedure for setting geometry and explained that if geometry is incorrect, autoconvergence may not operate correctly. It also documents the proper procedure for realignment of convergence after either an SSB module replacement or replacement of other components that directly or indirectly affect geometry or convergence. - Page 52 First Edition 0516 - First Printing Prepared by Thomson, Inc for TTE Technology, Inc. PO Box 1976 T-ITC222 Convergence Indianapolis, IN 46206 U.S.A.