Matsui 1410R, Service Manual

Page: 33 / 39

5.- DEFLECTION (Diagram E)
5.1- Frame deflection
This function is performed by the integrated circuit TDA3653 (7400).
- Frame supply (pins 6, 8, 9): Pin 9 is used to supply the IC except output stage which one is supplied by
pin 6. At pin 6 there is a higher voltage during flyback time. This is produced adding the flyback signal
present at pin 8 to a +25V. supply by D6416 and C2415. Pin 8 is also used to drive vertical flyback input at
pin 37 of the up. (IC 7600)
- Vertical input (pins 1, 3): The input circuit is driven by pin 44 of IC7015/6E. Vertical signal is amplified and
inverted.
- Vertical output (pin 5): Vertical output is applied to deflection coil. DC current is suppressed by C2404. A
voltage proportional to current deflection is present in R3411/12 and a feedback of it is sent to pin 42 of
IC7015/6 by 3407, so that amplitude can be adjusted by 3410. DC feedback is present in R3406. Linearity
is corrected by the network around C2405.
- TRC protection (pin 7): When frame deflection is broken down, the tube is protected blanking all the
picture by pin 7 output.
5.2- Line deflection
The final line transistor is driven by the transformer 5441, whose primary winding is driven by the transistor
T7440 connected to the line drive output of IC7015/6E.
The horizontal deflection stage is carried out in a conventional way, with the deflection transistor (T7445)
and line transformer (5545).
Beam current info (BCI) is present at C2460.
There are the following auxiliary supply voltages obtained from line transformer (5545):
+25V.: To supply frame deflection..
+12V.: To 8V. by IC7016 (diagram A) for small signal, +5V. by T7001 (diagram A) for the tuner
and for the microcontroller.
6.- MICROCONTROLLER/TEXT (Diagram E)
The CTN-BB chassis is designed to accept 2 different microcontrollers: SAA5531 and SAA5541.
Both microcontrollers are mounted in the same position (7600), and the associated circuitry is the same.
The ROM of the ICs contain an specific program that assures all the functions of the appliance, including a
MENU to control the set is (see Instructions Manual).
For no TXT sets SAA5541 is used.
For TXT sets SAA5531 is used which one also contains a teletext decoder, including the following functions:
TXT on/off, reveal, freeze, temporary cancellation, clock, subcode, zoom, index, flof, page +/-, X/26 and 8/
30 packet decoding (station identification and start-up page).
Following there is an explanation of the different functions of the microcontroller indicating pins number
assigned:
- Power supply (pins 31, 39, 44): The IC has s3,3V power supplies, analog (pin 31), core (pin 39),
and periphery ( pin 44 ). All supplies are present during stand by.
- P.O.R. (pin 43): POR (power on reset) is activated when the set is switched on (see 4.4 pag 13 ). If the
system shows abnormal behaviour it is important to reset it switching off/on the set. Reset can be produced
also connecting pin 43 to +5V. for an instant.
- LED (pin 20): The LED (6663) lights up with a low current when the television set is ON and with a high
current when the set is on Standby. While the set is receiving a remote control signal, the led is blinking.
- RC5 (pin 45): The commands transmitted by the remote control handset are received by infrared receiver
(1685) and passed to the microcontroller for decoding.
- Control keys (pins 10, 11, 12): When a control key is activated, the correspondent pin is connected to
ground.