Maintenance Service And Trouble Shooting - Haier 21FA18-T Service Manual

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4.Analysis of horizontal sync and horizontal scan output circuits
As the horizontal oscillation circuit is installed inside N201 (HAIER8873), Some brightness
signals including compound sync signals are transmitted to the internal sync segregation
circuits, where horizontal sync and vertical sync pulses are segregated. R321 (10K), R462
(12K) 、C452 (3900pF) 、VD436 and T401 are connected to N201 (13) are phase-lock
loop filters. Horizontal pumping signals are transmitted from (13) of N201 to horizontal
promotion transistor V431 (2SC2383), and then drive the H-DRIVE transformer. After
being amplified through it switches power transistor V432 (2SC5885) to control the
horizontal scan of the electronic-beam.C412 is a horizontal S correction capacitor and
L407 is for horizontal linear inductor. T401 is a horizontal output transformer. The
horizontal return pulse output from (7) of T402 is transmitted to pin (27) of N201 who
controls ABL circuits. ABL avoid high-voltage over rated value that will cause X-ray and
affect your health.
5.Analysis of video amplifying circuits
The video amplifying circuits are comprised of V901, V911, V921 and peripheral
components. R, G and B signals output from N201 (50), (51) and (52), 3 video power
transistor are available for amplifying the input R, G, B. White balance adjustment is
completed through N202 under control of an I

8. Maintenance Service and Trouble shooting

A. Principle integrated circuits
A1. 21 INCH color TV set composed of the following sections
(1) Small signal processing: super monolithic integrated circuits N201(Haier8873).
and memory N202 (AT24C08).
(2) Sound power amplifying: integrated circuits N301 ( AN7522N).
(3) Horizontal and Vertical scan output circuits: Vertical output integrated circuits
N401 (STV9302A), Horizontal output transistor V432 (2SC5885), Horizontal
flying back transformer T401 (JF0501-19910).
Switch power supply: switch transformer T601 (BCK-05I-5), power IC N601
(4)
(CQ0765).
input
VCC
PUMP UP
GND
output
OUT VCC
reference
2.61 0
26.56 0.45
2.21 0.5
0 0.9
16.31 0.68
26.87 0.5
2.62 0.65
2
C serial bus control system.
22
0
1.9
∞
1.25
1.75
2.95
1.3