- 19 -
(FIG.4)
ii. Convergence Adjustment (See Fig.4)
a. Receive a dotted pattern.
b. Unfix the convergence magnet clamper and align red with blue dots
at the center of the screen by rotating (R,B) static convergence magnets.
c. Align Red/Blue with green dots at the center of the screen by rotating
(RB-G) static convergence magnets.
d. Fix the convergence magnets by turning the clamper.
e. Remove the deflection yoke wedges and slightly tilt the deflection yoke
horizontally and vertically to obtain the good overall convergence.
f. Fix the deflection yoke by wedges.
g. If purity error is found, follow "PURITY ADJUSTMENT".
iii. +B Voltage check
After production aging, it is necessary to check +B voltage.
a. Receive standard colour bar signal.
b. Press key “I.P.C” to select “Natural” mode.
c. Connect digital voltmeter between C919 and GND.The read-out on the voltmeter should be +B±1V. If the result
is not satisfactory, adjust VR901 to make the voltage to be +B±1V.
C. Important notice
THE AKAI MODELS TABLED BELOW MUST BE PRESET TO PAL “BG” SOUND SYSTEM AT FACTORY
BEFORE SHIPMENT.
(THEY AREN’T AKAI MODELS NOW.)
PROCEDURE:
(1) TO MAKE ‘MASTER’ EEPROM WITH 1-99 CHANNELS PRESET IN PAL ‘BG’ SOUND SYSTEM
(1-99 CHANNELS CAN BE ‘MEMORIZED, IN PAL ‘BG’ SOUND SYSTEM ONE BY HAND)
(2) WITH THIS ‘MASTER’ EEPROM TO DUPLICATE OTHER EEPROM FOR ABOVE MODELS.
IN PRODUCTION LINE:
(1) INSERT THE DUPLICATED EEPROM INTO MAIN PCB OF ABOVE MODEL.
(2) ONLY USE THE FIRST 40 CHANNELS FOR TESTING AND EVALUATION WITH CENTRAL SYSTEM
SIGNAL, CABLE CHANNELS OR SIGNAL FROM PATTERN GENERATOR.
(3) AT FINAL STAGE, TO SET THE SOUND SYSTEM OF THE TV SET ‘BG’ SYSTEM AND FEED CENTRAL
SYSTEM SIGNAL TO THE TV SET , PERFORM THE ‘APS’ TUNING AGAIN IN SAME PROCEDURE AS
DESCRIBED IN THE OPERATION MANUAL. THIS CAN GUARANTEE ALL CHANNELS ARE ‘BG’ SYSTEM.
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