TOSHIBA 28ZH37P
Service Manual

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE �X-RAY RADIATION PRECAUTION�, �SAFETY PRECAUTION� AND �PRODUCT SAFETY NOTICE� ON PAGE 3 OF SERVICE MANUAL.

SET-UP ADJUSTMENT (FOR FLAT TUBE)
I The following adjustments should be made when a complete realignment is required or a new picture tube is installed. Perform the adjustments in order as follows : 1. Color Purity 2. Convergence 3. White Balance Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning. Refer to figure 1. COLOR PURITY ADUSTMENT (1)Let the screen face in the installing direction or toward the east (when it is to be moved), bring up the service mode screen after demagnetizing (front, left, right, and top) with the degaussing coil, receive white signals by pressing the [TV/VIDEO] button, and then the receiver should be operated for more than 40 minutes. (2)Perform rough adjustment of the central convergence with the P/C magnet according to the adjustment item. (3)Receive built-in green signals, loosen set screws on the deflection yoke, remove rubber wedges, and shift the deflection yoke to toward front. (4)Move alternately the two 2-pole magnets of the P/C magnets so that the green raster can come to the center of the screen. Figure 1.

SPECIFIC INFORMATIONS GENERAL ADJUSTMENTS

2-pole purity magnet (27": Magnet is fixed with deflection yoke.)

Green Belt

Main 4-pole convergence magnet (30" : 32") 6-pole convergence magnet (34") 6-pole convergence magnet (30" : 32") Main 4-pole convergence magnet (34") P/C magnet installing position A � 30"=26.5 mm � 32"=30.5 mm or 32.5 mm A � 34"=37 mm � 34"=39 mm Sub-4-pole convergence magnet (32" : 34") Sub-4-pole convergence magnet (to be installed on deflection yoke for 30", 32�)

(5)Receive built-in red and blue signals, check that there is no inclination of the single color raster toward one side, and if each color tilts to a great extent, make adjustment with the 2-pole magnet so that the 3 colors will come to the center evenly. Shift deflection yoke (6)Receive the green raster, shift the deflection yoke from a foremost position (hitting against the picture tube) to a backward position horizontally, stop the deflection yoke at a position where it begins to become a green raster, and perform accurate marking on the picture tube. (7)Shift the deflection yoke further backward, and perform accurate marking at a position where the green raster begins to being luck. (8)Fix the deflection yoke at a position 60% forward within the range marked in items (6) and (7) above. CONVERGENCE ADJUSTMENTS I CENTER CONVERGENCE: (1)Receive the white crosshatch or dot pattern from the service signal generator. (2)Use the 2 pieces of main 4-pole magnets of P/C magnets, change the open angle, and align the red and blue vertical lines on the screen center. (3)Freeze the open angle of the main 4-pole magnets, turn them simultaneously, and align the horizontal lines. (4)Take the same steps for items (2) and (3) above and align red/blue with green on the screen center using two 6-pole magnets.
P/C Mag 100 60 0% Fix the deflection yoke at a position 60% forward from a point between (6) and (7) (6) (8) (7) Perform marking of each point on the tape of picture tube

Picture tube

CRT-D board

* Adjust the convergence magnet to get vest convergence in the the order to (1) ~ (5).

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