PHOTOFACT, Technical Service Data

INDEX SONY Adjustment and Alignment Tools .... 1 Model W-27EXR25 (Chassis SCC-D50F-A) Convergence Adjustments ...... 6 GridTrace Location Guide ABoard ...... 8 ..9 GBoard ...... 9 .8 PBoard-TopBoard ...... 8 UlBoard .9 ...... 9 Important Parts Information ...... 10 Miscellaneous Adjustments ...... 6 PartsList ...... 9,10,11 Photos ABoard ...... 7,8 CBoard ...... 9 Cabinet - Rear View ...... 1 CRT Neck Assembly ...... 6 GBoard ...... 9 HBoard ...... 8 PBoard-BottomBoard ...... 7,8 PBoard-TopBoard ...... 7,8 Ul Board ...... 4,9 Complete coverage U2Board ...... 8,9 for servicing a television receiver... ! Troubleshooting Quick-Checks ABoard ...... 7 CBoard ...... 9 l Schematics l Parts lists PIP Adjustments ...... 6 Placement Chart ...... 5 l Component l Troubleshooting Safety Precautions ...... 1 locations guide Safety Related Adjustments ...... 6 Schematics CRT ...... 2 Control ...... Coverage includes this additional model and chassis: D/A Converter ...... 2 MODEL CHASSIS MTS Decoder ...... 3 KV-27EXR20 SCC-DSOE-A PIP ...... 4 Power Supply ...... 4 Television ...... 2 Terminal Guides and Notes ...... 7 Test Equipment ...... 1 Troubleshooting ...... 1 Tuner Terminal Guide ...... 6 Tuner Voltage Chart ...... 6

For Supplier Address, HOWARD W. SAMS & COMPANY See PHOTOFACT Annual Index DECEMBER 1991 SET 2910 TROUBLESHOOTING

POWER SUPPLY HORIZONTAL

Check AC F60 1. Determine if the TV is in shutdown: If F60 1 is open: Refer to the “High Voltage Shutdown” section of this Troubleshooting guide. Check Bridge (D601, and D602), (R601), . C601, C603 thru C606, Electrolytics C607, If the TV is not in shutdown, inject a horizontal signal at the base of and C650, Power Converter IC (IC65 l), and Power the Horizontal Output (4502). (T604). If horizontal deflection is now present: Apply 120V and check for 17.OV at the (+) lead of D602. Check the voltages, waveforms, and components associated If 17.OV is missing: with pins 37,39,41, and 45 of Y/C/J IC (IC301), and Horizontal Drive Transistor (Q501). Check Line Filters (T601, T602), Power Transformer (T604), Capacitors C608, C609, Electrolytic C610, and D602. If there is no horizontal sweep: If 17.OV is present, check for 15OV* at the (+) lead of D601. Check the voltages, waveforms, and components associated with 4502, and Horizontal Output Transformer (T500), and If 15OV* is missing: check components associated with Diodes D5 17, D5 19, D520, Check the voltages, waveforms, and components associated D521, and D531 for defects. with Power (RY601), and Relay Driver Transistor The high voltage rectifier is part of T500 and if defective will effect (Q601), and D601. the performance of the horizontal circuits. Note: The set may be in shutdown. Refer to the “High Voltage If the horizontal oscillator is off frequency: Shutdown” section of this Troubleshooting guide. Check the voltages, waveforms, and components associated If 15OV* is present at the (+) lead of D601, check for the proper wa- with AFC-DET Transistor (Q307), and Buffer Transistor veform at pin 1 of IC65 1. (Q3W. If the waveform is missing: Horizontal linearity or foldover problems may be caused by Capaci- Check the voltages, waveforms, and components associated tors C506, C507, and C509 beiig defective. with IC65 1, Transfer IC (IC652), Converter Transformer (T651), and Soft Start Transistor (4612). If the proper waveform is present at pin 1 of IC65 1: VERTICAL Check the voltages, waveforms, and components associated Inject a vertical drive signal at pin 3 1 of Y/C/J IC (IC301). with T6.5 1. If vertical deflection is now present: * Taken from isolated ground. Check the voltages, waveforms, and components associated with pins 29 thrn 34,38, and 44 of IC301. HIGH VOLTAGE SHUTDOWN If there is still no vertical deflection: Check the voltages, waveforms, and components associated The high voltage is monitored by D531, rectifying pulses with Vert Out IC (ICSOO). from the Horizontal Output Transformer (T500). Should the high ,voltage increase, the rectified voltage at the cathode of Diode D531 Vertical linearity or foldover problems may be caused by pincush- will also increase, This will cause the voltage at pin 8 of Protect ion, vertical feedback and bias circuits: Module (PM501) to increase and turn on Protect (Q607, Check the voltages, waveforms, and components associated 4608) which causes Relay Drive Transistor (4601) to turn off and with Pin Correction IC (IC531) and Pin Out Transistor (4530). remove power from the set. Also check Electrolytics C328, C538, C540, C562, C563, and To troubleshoot, remove Resistor R629 fom the circuit. Use a variac C566 for defects. for AC power. Start at 90VAC and increase as necessary to locate and repair the defect. Return R629 to the circuit. Note: Care should be taken in defeating the high voltage shutdown IF-AGC circuit, as this may cause excessive X-radiation and damage the CRT, TSOO, and associated components. Monitor the high voltage Inject a signal at the IF input and check for video on the CRT. and troubleshoot. If video is present: Check the tuner, tuner control, and tuner AFC circuits. TROUBLESHOOTING continued

If there is no video on the CRT, check for a video waveform at Check the voltages, waveforms, and components associated TP12. with pins 3,4,8,26, and 27 of Y/C/J IC (IC301), Buffer Transistors (43 lO,Q3 13), Gamma Comp 1 Transistor (43 15), If video is present at TP12: and Equalizer Transistor (43 14). Y Clamp Transistor (43 17), Refer to the “Video” section of this Troubleshooting guide. and Gamma Comp 2 Transistor (4316). If there is no video at TP12: If brightness is inadequate or camrot be controll& Check the voltages, waveforms, and components associated Check the voltages, waveforms, and components associated with IF Module (IF201), and AGC Mute Transistor (Q102). with pin 5 of v901. A defective AGC circuit can cause an overloaded picture, excessive snow or loss of audio and video. CHROMA See the AGC Voltage Chart for AGC voltages with signal. Check for a chroma waveform at pm 5 of Y/C/J IC (X301). AGC Voltage Chart If the waveform is missing: IF201 pm 1 5.3v Check the voltages, waveforms, and components associated with Buffer Transistor (Q417), C- IC (IC403), and pin 4 of Comb Filter (CM1301). SYNC If chroma waveform is present at pin 5 of IC30 1, cheek for the pmp er waveforms at pins 20,22,24 of IC301. If there is no vertical or horizontal sync: If these waveforms are missing: Check the voltages, waveforms, and components associated Check the voltages, waveforms, and components associated with Y Buffer Transistor (4301). with pins 5,6,7,19 thru 25 of IC301. If there is no vertical sync: Check the 3.58MHz oscillator at pin 7 of IC301. Check the voltages, waveforms, and components associated If the proper wavforms are present at pins 20,22,24 of IC301: with pins 38, and 44 of Y/C/J IC (IC301), V/Sext 1 Transistor (Q302), V/Sext 2 Transitor (Q303), and V/Sext 3 Transistor Refer to the “Raster” section of this Troubleshooting guide. (Q3W. If there is no horizontal sync: RASTER Check the voltages, waveforms, and components associated with pins 41, and 45 of IC301. Check the CRT and CRT voltages. Cheek the voltages, waveforms, and components associated with Buffer Transistor (Q711), SW 1 Transistor (Q710), and SW 2 Transistor (4712). VIDEO If there is no Red: Inject a signal at TP12, and check for video on the CRT Cheek the voltages, waveforms, and components associated with pin 20 of Y/C/J IC (IC301), Red Output Transistor (4708). If video is present: Video Amp Transistor (Q709), and Red 1K Det Transistors Refer to the “IF-AGC” section of this Troubleshooting guide. (Q707,Q7 16). If there is no video on the CRT, check for a video waveform at pin 6 If there is no Green: of Comb Filter (CM1301). Check the voltages, waveforms, and components associated If video is missing at pm 6 of CM1301: with pin 22 of IC301, Green Output Transistor (Q704), Video Amp Transistor (Q705), and Green 1K Det Transistors (4706, Check the voltages, waveforms, and components associated 47 15). with Buffer Transistors (4409, Q410), and AV-Switch IC (IC444), and CM1301. If there is no Blue: If video is present at pin 6 of CM1301, check for a video waveform Check the voltages, waveforms, and components associated at the emitter of Y Amp Transistor (4305). with pm 24 of IC301, Blue Output Transistor (Q701), Video Amp Transistor (Q702), and Blue 1K Det Transistors (4703, If the video is missing: 47 14). Check the voltages, waveforms, and components associated If the raster has a keystone shape: with 4305, Buffer Transistor (Q416), and Y Switch IC (IC402). Check the Deflection Yoke (L550). If the waveform is present at the emitter of 4305: SET 2910 Page 1 TROUBLESHOOTING continued

If the raster has height or width problems: Check the voltages, wavefotms, and components associated with pins 10 thru 13 of IC2104, Vertical Pulse Transistor Refer to “Vertical”, “Horizontal”, and “Power Supply” sections (Q2119), and pins 5 and 36 of Y/C/J IC (IC2103). of this Troubleshooting guide. If waveform is present at pin 23 of IC2204, check for the proper wa- veform at pin 61 of IC2204. AUDIO If waveform is missing:

Select an active TV channel and check for an audio waveforms at Check the voltages, waveforms, and components associated pins 1 and 2 of MTS Decode IC (IC25 1). with pins 1 and 2 of IC2 104, and Buffer Transistor (43 12) If there is no audio: If waveform is present at pin 23 of IC2204: Check the voltages, waveforms, and components associated Check the voltages, waveforms, and components associated with IC25 1, and pin 10 of IF Module (IF201). with IC2204. If audio waveforms are present at pins 1 and 2 of IC251, cheek for audio waveforms at pins 1 and 5 of Audio Amp IC (IC405). PIP SYNC If audio waveforms are missing: If there is no vertical or horizontal sync: Check the voltages, waveforms, and components associated with Audio Buffer Transistors (4430, Q431), and Buffer Check the voltages, waveforms, and components associated Transistors (4202,Q203). with V Buffer 3 Transistor (Q2125), and Buffer Transistor (42130). If audio waveforms are present at pins 1 and 5 of IC405: If there is no vertical sync: Check the voltages, waveforms, and components associated with IC405, Audio Mute Transistors (4432, Q433), and Mute Check the voltages, waveforms, and components associated Transistor (Q 103). with pm 5 of Y/C/J IC (IC2103). If there is no horizontal sync: PIP HORIZONTAL Check the voltages, waveforms, and components associated with pin 4 of IC2103. Check for the proper waveforms at pin 9 of A/D Conv IC (IC2206), and pin 24 of PIP Control IC (IC2204). If the waveforms are missing: PIP VIDEO Check the voltages, waveforms, and components associated Check for the proper waveform at pin 34 of Y/C/J IC (IC2103). with pins 4,6 thru 10, and 28 of Y/C/J IC (IC2103), pins 8 and If video is missing at pin 34 of IC2 103: 9 of IC2 104, Horizontal Pulse Transistor (42 120), Horizontal Out Transistor (4212 l), and Horizontal Drive Transistor Cheek the voltages, waveforms, and components associated (42122). with V Buffer 1 Transistor (Q2245), V Buffer 2 Transistor (Q2123), Buffer Transistor (Q413), and AV-SW IC (IC444). If waveforms are present, cheek for the proper waveform at pin 60 of IC2204. If video is present at pin 34 of IC2103, check for a video waveform at pin 16 of A/D Conv IC (IC2206). If waveform at pin 60 of IC2204 is missing: If the waveform is missing: Check the voltages, waveforms, and components associated with Horizontal Width IC (IC2 102), Horizontal Pulse Transistor Check the voltages, waveforms, and components associated (Q2117), and pin 39 of Y/C/J IC (IC301). with Y Out Transistor (Q2139), Y Buffer 2 Transistor (Q2102), Y Amp Transistor (42 10 l), Y Buffer 1 Transistor (42 116), and If waveform at pin 60 of IC2204 is present: pins 14,21,23,25,30,32,33, of Y/C/J IC (IC2103). Check the voltages, waveforms, and components associated If waveform is present at pin 16 of IC2206, check for the proper wa- with IC2204, and IC2206. veform at pm 4 of Y D/A Conv IC (IC2201). If the waveform is missing at at pin 4 of IC2201: PIP VERTICAL Check the voltages, waveforms, and components associated with IC2201, pins 1,46 thru 5 1, and 54 of IC2204. Check for the proper waveform at pin 23 of PIP Cont IC (IC2204). Cheek for the proper waveform at the emitter of YS Buffer Trans- If the waveform is missing: mitter (42244). TROUBLESHOOTING continued

If the wave form is missing at the emitter of 42244: Check the voltages, waveforms, and components associated with 42244, pins 3 thru 6 of IC2 104, and pin 3 1 of IC2204. If the waveform is present at pin 4 of IC2201: Check the voltages, waveforms, and components associated with Y Buffer Transistor (42202).

PIP CHROMA

Check for the waveforms at pins 20 and 22 of\Y/C/J IC (IC2103). If the waveforms are missing: Check the voltages, waveforms, and components associated with pins 16 thru 22, and 31 of IC2 103. Check the 3.58MHz oscillator at pins 15 and 18 of IC2103. Check the voltages and components associated with Sub Color Control and pin 13 of IC2103. Check the voltages and components associated with Sub Hue Control and pin 12 of IC2103. If chroma waveform is present at pins 20 and 22 of IC2103, check for the proper waveforms at pins 17 and 18 of A/D Conv IC (IC2206). If the waveforms are missing at pins 17 and 18 of IC2206: Check the voltages, waveforms, and components associated with R-Y Out Transistor (Q2103), and B-Y Out Transistor (42114). If the waveforms are present at pins 17 and 18 of IC2206, check for the proper waveforms at pins 4 of R-Y D/A Conv IC (IC2202), and B-Y D/A Conv IC (IC2203). If the waveforms am missing at pin 4 of IC2202, and IC2203: Check the voltages, waveforms, and components associated with IC2202, IC2203, PINP Conv IC (IC2204), and IC2206. If the waveforms are present at pin 4 of IC2202, and IC2203: Check the voltages, waveforms, and components associated with R-Y Buffer Transistor (Q2203), B-Y Buffer Transistor (Q2204), Red Drive Transistor (Q2106), Blue Drive Transistor (Q2107), and Green Drive Transistor (42109).

SET 2910 Page 1

MISCELLANEOUS ADJUSTMENTS

PRETUNING 3. Make changes on selected adjustment by pressing the 3 and 6 button. Note: Use Remote Commander to accomplish prehming. All proce- dures require an antenna or cable connected, and power supplied to Saving Adjustments to Memory the set. 1. Adjustments must be saved to memory. Auto Memory 2. To save adjustment, press the Mute button and then the Enter button. 1. Press the Auto Program button. Memory Write Confirmation Add Channel 1. Disconnect AC plug from outlet. 1. Select Channel. 2. Plug set in and enter Service Adjustment Mode. 2. Press Add button. 3. Select adjustment and confirm that setting was saved to 3. Repeat steps one and two to add other channels. memory.

Delete Channel Exiting Service Adjustment Mode 1. Select Channel. 1. Turn set off and then back on. 2. Press Erase button. 3. Repeat steps one and two to erase other channels. Adjustments Required When Replacing IC’s IC102: VSOM, AFC, REF, ROFF, GOFF, BOFF, ABLM, Guide Function TEST, DRGB. 1. Press the Guide button to select Tie, Timer, and Channel IC251: MPX, FILO, DEEM, STEV, SAPV, PILO, SEP, VD, Block. LVOL, RVOL. 2. Select function by pressing guide button until desired IClOl: DISP function is highlighted. Press Enter button. IC301: HFRE, VFRE, VPOS, VSIV, VLIN, VSCO, HPOS, 3. Follow the displayed instructions. HSIZ, PAMP, CPIN, PPHA, VCOM, GAMP, BAMP, GCUT, BCUT, CROM, SPIX, SHUE, SCOL, SBRT, RGBP, Sleep VSOM, AFC, REF, ROFF, GOFF, BOFF, ABLM. 1. Press Sleep button. The set will turn off automatically in approximately one hour. VSMO, AFC, REF, ROFF, GOFF, BOFF, ABLM, TEST, 2. To cancel sleep timer, press Sleep button until Sleep Off is DRGB indicated or turn set off. following adjustments have the listed initial settings. Save each Note: This set employs digital customer controls. Use the Remote The adjustment to memory before performing the next one. Enter the Commander to accomplish digital adjustments. Unless specified all Service Adjustment Mode. Adjust the level of VSOM to 00, AFC to adjustments are accomplished with controls in reset position. 00, REF to 02, ROFF to 01, GOFF to 01, BOFF to 01, ABLM to 01, TEST to 00, DRGB to 01. DIGITAL ADJUSTMENT PROCEDURES DISPLAY POSlTlON (DISP) Entering Service Adjustment Mode Enter the Service Adjustment Mode. Select DISP adjustment. Adjust 1. Tune in a picture, and turn set off. the level to center the display 2 l/2 inches on either side. Save ad- 2. Insert a small tuning tool in service mode access hole, justment to memory. located to the left of the right speaker connections on the back of the set. While depressing Service Button (SW900), turn set on. HORIZONTAL FREQUENCY (HFRE)

Making Adjustments Tune in a colorbar pattern. Enter the Service Adjustment Mode. Se- lect the AFC Adjustment and set the AFC to 03. Horizontal will lose 1. Enter service mode. sync. Select HFRE adjustment. Adjust the level until the picture 2. Select adjustment by pressing the the 1 and 4 buttons. locks in. Save adjustment to memory. Select AFC adjustment and set level to 00. Save adjustment to memory. Page 6 SET 2910 PIP ADJUSTMENTS

Note: Adjustments made with PIP on. Refer to “Digital Adjustment PIP RGB PICTURE (RGBP) Procedure” in Miscellaneous Adjustment Section. Tune in a colorbar Pattern. Enter Service Adjustment Mode. Select RGBP adjustment, and adjust level to 00. Set Picture and Brightness PIP BRIGHTNESS AND CONTRAST to MINIMUM. Adjust RGBP for proper colorbars in PIP window. Save adjustment to memory. Tune in a picture. Set Brightness, Color, and Picture to MINIMUM. Adjust Bright Level Control (RV2 105) for just visible highlights. Set Picture and Brightness to Maximum and adjust Contrast (RV2108) PIP B-Y for minimum blooming. Set Picture, Brightness, and Color to reset. Tune in a colorbar pattern. Turn B-Y Control (RV2200) clockwise until PIP window turns solid blue and note position. Turn RV2200 PIP WINDOW POSITION counterclockvise until PIP window colorbars lose blue and note position. Set RV2200 to midpoint between the two positions. Tune in a picture. Place PIP window in upper left comer of semen. Adjust Position Control (RV2103) to place PIP window 1 inch from left side of screen. Place PIP window in lower right comer of screen. PIP R-Y Adjust Position Control (RV2103) to place PIP window 1 inch from right side of screen. Tune in a colorbar pattern. Turn R-Y Control (RV2201) counter- clockwise until PIP window turns solid red and note position. Turn RV2201 clockwise until PIP window colorbars lose red and note PIP SUB COLOR/SUB TINT position. Set RV2201 to midpoint between the two positions.

Tune in a colorbar pattern on the PIP screen. On main screen select a video input with no signal. Position PIP screen in lower left comer SUB PICTURE of screen. Connect an oscilloscope to TP47B. Adjust Sub Color Con- trol (RV2 107) so that the PIP portion of the signal is 1.9V p-p. Tune Tune in a colorbar pattern on the PIP window. Adjust LC Networks in a picture on PIP window. Adjust Sub Hue Control (RV2106) to (PL2205, PL2206) so that the PIP window size and location is identi- obtain proper skin tones. cal in all positions. MISCELLANEOUS ADJUSTMENTS continued

HORIZONTAL SIZE (HSIZ) VERTICAL COMP (VCOM)

Tune in a crosshatch pattern. Enter the Service Adjustment Mode. Enter the Service Adjustment Mode. Select VCOM, and adjust level Select HSIZ, and adjust level for slight horizontal overscan. Save ad- to 02. Save adjustment to memory. justment to memory.

CHROMA TRAP (CROM) HORIZONTAL CENTER (HPOS) Tune in a colorbar pattern. Set Color to Maximum, and turn NOTCH Perform Horizontal Frequency Adjustment. Tune in a crosshatch pat- on. Connect an oscilloscope to TP47R (On C-Board). Enter the Ser- tern. Adjust Horizontal Centering Connector (A-55) for best horizon- vice Adjustment Mode. Select CROM, and adjust level for MINI- tal centering. Enter the Service Adjustment Mode. Select HPOS, and MUM chroma. Save adjustment to memory. adjust level for best horizontal centering. Save adjustment to memory. SUB BRIGHTNESS (SBRT) PINCUSHION (PAMP, CPIN, PPHA) Tune in a crosshatch pattern. Set Picture and Brightness to MINI- MUM. Enter the Service Adjustment Mode. Select SBRT, and adjust Tune in a crosshatch pattern. Enter the Service Adjustment Mode. level for visible highlights. Save adjustment to memory. Select PAMP, and adjust level for straight vertical lines at left and right of screen. Save adjustment to memory. Select CPIN, and adjust level for straight vertical lines at top and bottom of screen. Save ad- SUB CONTRAST (SPIX) justment to memory. Select PPHA, and adjust level for equal spacing of vertical lines from top to bottom of screen. Save adjustment to Tune in a crosshatch pattern. Enter the Service Adjustment Mode. memory. Select SPIX, and adjust level for best picture. Check tracking by ad- justing Picture and Brightness to MINIMUM and Maximum and check for blooming. Readjust if necessary. Save adjustment to VERTICAL FREQUENCY (VFRE) memory.

Tune in a colorbar pattern. Enter the Service Adjustment Mode. Se- lect VFRE adjustment, and adjust the level until the picture locks in. Save adjustment to memory. SUB HUE AND SUB COLOR (SHUE, SCOL)

Tune in a colorbar pattern. Connect an oscilloscope to TP47B (On VERTICAL SIZE (VW) C-Board). Enter the Service Adjustment Mode. Select SCOL, and adjust level for 3.W p-p. Tune in an active channel. Select SHUE, Tune in a crosshatch pattern. Enter the Service Adjustment Mode. and adjust level for proper skin tones. Save adjustment to memory. Select VSIZ, and adjust level for slight vertical overscan. Save ad- justment to memory. S - CORRECTION (VSCO)

VERTICAL POSITION (VPOS) Enter the Service Adjustment Mode. Select VSCO, and adjust level to 0. Save adjustment to memory. Tune in a crosshatch pattern. Enter the Service Adjustment Mode: Select VPOS, and adjust level to center picture vertically. Save ad- justment to memory. COLOR PURITY

Use a degaussing coil to demagnetize the CRT and mounting brack- VERTICAL LINEARITY (VLIN) ets. Enter the Service Adjustment Mode. Adjust ROFF and BOFF levels to MINIMUM. Adjust GOFF for a green raster. Loosen Tune in a crosshatch pattern. Enter the Service Adjustment Mode. Deflection Yoke clamp screw and slide it backward to obtain a verti- Select VLIN, and adjust level for equal vertical spacing of pattern. cal green band. Adjust purity rings to center the vertical green band. Save adjustment to memory. Slide the Deflection Yoke forward until a uniform green screen is obtained. Check Blue and Red purity by adjusting the ROFF, GOFF, and BOFF levels. Return all controls and adjustments to normal lev- els. SET 2910, Page6 MISCELLANEOUS ADJUSTMENTS continued

COLOR TEMPERATURE @CUT, GCUT, GAMP, BAMP) (RV702) to converge the Red and Blue dots over the Green dots horizontally at the center of the screen. Rotate the Vertical Static Adjust G2 Control (RV701) so that the retrace lines just disappear. Magnets to converge the Red and Blue dots over the Green dots ver- Tune in a crosshatch pattern. Enter the Service Adjustment Mode. tically at the center of the screen. NOTE: Some versions use a BMC Set Picture to MINIMUM. Select SBRT adjustment, and adjust level magnet. To adjust the BMC magnet, slide it in and out to correct for for MINIMUM. Select GCUT and BCUT adjustments and adjust lev- insufficient horizontal static convergence, rotate the BMC magnet to els for best white balance. Save adjustment to memory. Set Picture correct for insufficient vertical static convergence. Tune in a cross- to Maximum. Select GAMP and BAMP adjustments and adjust lev- hatch pattern and loosen the Delection Yoke (L550) screw. Remove els for best white balance. Save adjustment to memory. Perform Sub the rubber wedges between the Deflection Yoke and the CRT. Tilt Brightness Adjustment. the Deflection Yoke up or down to converge the vertical lines at top and bottom of screen and the horizontal lines at the right and left sides of the screen. Tilt the Deflection Yoke right or left to converge CONVERGENCE the vertical lines at the right and left sides of the screen and the hori- zontal lines at the top and bottom of the screen. Repeat convergence Adjust the Focus, Horizontal Size, Vertical Size, and Vertical Lii- procedure if necessary to obtain best overall convergence. Apply earity. Tune in a dot pattern. Adjust the Horizontal Static Control adhesive to wedges and carefully replace on CRT.

CRT NECK ASSEMBLY

- PURITY MAGNET

,V STAT MAGNET

WC MAGNET SAFETY RELATED ADJUSTMENTS

R559 CONFIRMATION METHOD (HOLD-DOWN 2. Confum that the voltage at TP-85 is more than 108V when CONFIRMATION) AND READJUSTMENTS the set is operating normally with 120VAC supply.

The following adjustments should always be performed when replac- ing the following components PMSOl, 4608, 4607, R629, R628, Hold-down Operation Confirmation R627, R559. 1. Turn the Power switch on, and receive a white screen. Preparation Before Confirmation. Adjust ABL current to 1650 +/- 8OuA with Picture and Bright controls. 1. Remove R675 on the G board and connect a variable resistor (RVl about 10K) between pin 1 of IC653 and B+ 2. Gradually apply DC voltage to TP-85, and confirm that the line. voltage is less than 137.5V when raster disappears during operation of the hold-down circuit. 2. Supply 12OVAC +/- 2.0VAC with variable transformer. Note: When the hold-down circuit starts operating, turn the set off immediately. Hold-down Operation Confirmation 3. Turn the Power switch on, and receive a dot pattern. Adjust 1. Turn the Power switch on, and receive a white signal. ABL current to 150 +/- 5OuA with Picture and Bright Adjust ABL current to 1650 +/- 80uA with Picture and controls. Bright controls. 4. Gradually apply DC voltage to TF-85, and confirm that the 2. Increase B+ line voltage gradually by adjusting the voltage is less than 138.5V when raster disappears during resistance of RVl . Confirm that the MINIMUM voltage is operation of the hold-down circuit. less than 143SV when the raster disappears during Note: When the hold-down circuit starts operating, turn the operation of the hold-down circuit. set off immediately. Note: When the holddown circuit starts operating, turn the set off immediately. Holddown Readjustment 3. Turn the Power switch on, and receive a dot pattern. Adjust 1. If Hold-down Operation Confiition cannot be satisfied, ABL current to 150 +/- 50uA with Picture and Bright readjustment should be performed by altering the resistance controls. value of R570. 4. Increase B+ line voltage gradually by adjusting RVl. Confvm that the MINIMUM voltage is less than 146.W when the raster disappears during operation of hold-down B+ VOLTAGE CONFIRMATION circuit. Note: When the hold-down circuit starts operating, turn the The following adjustment should always be performed when replac- set off immediately. ing IC653 and R675. 1. Supply 130VAC +/- 1VAC with variable auto-transformer. Holddown Readjustment 2. Receive a monoscope signal. 1. If Hold-down Operation Confirmation cannot be satisfied, readjustment should be performed by altering the resistance 3. Set Picture and Bright controls to initial reset position. value of R559. 4. Confii that the voltage at TP-91 is less than 137V. 5. If step 4 cannot be satisfied, replace IC653 and R675. R570 CONFIRMATION METHOD (HOLD-DOWN Repeat above steps. CONFIRMATION) AND READJUSTMENTS

The following adjustments should always be performed when replac- ing the following components IC653, PM501, 4608, 4607, D531, C545, C627, R570, R591, R627, R628, R675, T500

Preparation Before Confirmation. 1. Turn the Power switch on, and receive a white signal. Set the Picture and Bright controls to Maximum.

Courtesy of Manufacturer