Toshiba 43A9UA, Service Manual

Page: 17 / 106

– 17 –
GENERAL ADJUSTMENTS
CONVERGENCE ADJUSTMENT
1. PICTURE ADJUSTMENT
The adjustment are done on two screens; 50 Hz mode (PAL)
and 60 Hz mode (NTSC). To synchronize correction wave to
each frequency, receive the suitable signal.
Note: The convergence circuit is a circuit to eliminate screen
distortion and can not make a drastic correction such
as to correct entire screen size. An excessive correction
may actuate the protection circuit. So a care will be
necessarry.
1-1. Change of Memory (E 2 PROM)
Memory of Q711 E 2 PROM is nonvolatile, and adjusted data is
stored. Since data in RAM of Q701 is eliminated with power
OFF, the RAM is set by soft command of micro-processor QA01
at every power ON. The adjusted data which is obtained from
screen-watching is once stored in RAM inside Q701. The whole
data in RAM which is corrected on each adjusting point and is
changed, is saved into E
2 PROM (Q711) as a fixed data. The
data capacity per one screen requires 8k for 50 Hz mode (PAL),
and 4k for 60 Hz mode (NTSC).
1-2. Service Mode
1-2-1. Outline
Service mode is controlled by software of micro-processor
QA01, and is one of function of set.
This mode is designed so that ordinary user cannot use this,
and special operation is required to use this.
Data change is done by direct shift (cursor display) of adjust-
ing points; 50 Hz mode (PAL) 8
x
8/1 color and 60 Hz mode
(NTSC) 8
x
7/1 color.
1-2-2. To Enter and to Exit
Press mute (
o
) key on remote hand unit at twice, and keep
pressing, then press MENU key of set console. The service
data will be display on the top left screen. Under this condition,
press "F+
8
" keys on remote hand unit. The CONVER ADJUST
MENU will appear on the screen. Further, press "F+
8
" again,
the screen returns to original picture.
o
+
o
+ MENU
F +
8
KEY
+ KEY
+ KEY
s
or
t
MENU Selection
SCREEN
adjustment
F +
8
KEY
S
Service data display
Exit from CONVER ADJUST MENU
After saving DATA (And return to MENU)
ADJUSTING SCREEN
CONVER ADJUST MENU
1: ADJUST PAL 50Hz
2: PAL TO NTSC
3: ADJUST NTSC 60Hz
Menu Screen
Note: Before proceeding to the adjustment for each screen, always perform the adjustments for vertical size (HIT) and horizon-
tal size (WID) with the main deflection data changed.
1-2-3. Adjustment menu
Order of the adjusting screens is PAL 50Hz
→
NTSC 60 Hz
The menu order is 1
→
2 (Data conversion).—when the vertical sync is 50 Hz.
Next menu order is 3.—when the vertical sync is 60 Hz.
No. Item Description
1 ADJUST PAL 50Hz Allows manual adjustment in PAL mode.
Perform the adjustments according to dimensions specified.
2 PAL TO NTSC Automatically saves auxiliary forecasted data of NTSC 60 Hz screen by referring PAL 50 Hz
screen.
The calculated data are saved on NTSC 60 Hz screen, and then the operation completes.
In this case, NTSC 60 Hz screen is created through the calculation process. Perform check in
manual mode, and if there are some problems in color deviation, distortion, etc., correct them.
When ececuted with this menu selected, NTSC 60 Hz screen is modified again, so care will
be necessary.
3 ADJUST NTSC 60 Hz Allows manual adjustment for NTSC 60 Hz screen.
Select this mode when performing adjustment for color matching and correction of distortion
for NTSC 60 Hz are required.
Perform the adjustments according to dimensions specified.