Hisense HSM515AV User manual

SERVICE MANUAL
HSM515AV
51CM CTV
SEP04 SERVHSM515AV

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Hisense UOC 2004-10-15
21 ¨ & 14 ¨ Color TV Service Manual
Catalogue
1. Technology Specification and Feature…..……………………… Page 1
2. The IC list …………………………………………………… Page 2
3. Signal process……………………………………………………… Page 2
4. The horizontal and vertical circuit………………………………… Page3
5. Power supply……………………………………………………….. Page 3
6. Appendix 1…………………………………………………………..Page 4
7. Appendix 2....………………………………………………………..Page 9
1．Technology Specification and Feature
I
2C Bus Control
Auto Search
Off/On Timer
Rated Voltage: AC 140V-250V 50Hz/60Hz
Sound output: 5 W×2
Screen size Picture tube 54 cm
System: Color Sound
RF PAL B.G
AV NTSC
Channel coverage: VHF Low channel (VL) =48.25 to 147.25 MHz
VHF high channel (VH) =154.25 to 463.25 MHz
UHF channel U) =471.25 to 863.25 MHz
IF 38.9MHz
External input/output Video/Audio(L/R)2 set input
S-Video input
YUV input
Video/Audio(L/R) 1 set output

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2. IC list
Table 1, the main IC and functions
Number Function IC Remark
1 Power supply KA5Q0765RT N611
2 CPU + SIGNAL PROCESSER OM8370/TDA9370 N301
3 Field driver STV9302A N401
4 Sound driver AN7522N N161
5 AV SWITCH TC4052BP N801 (Video)
N121(sound)
6 Memory AT24C08 N702
7 Photo-coupler HS817B N504
8 IR-receiver HS0038A N1503
9 8V Regulator L7808CV N503
10 5V Regulator L7805CV N505
3. Signal process
The TV signal enters into tuner (A201) from cable or antenna. Pin 10 and pin 11 of N301 are
combined to select the band. Pin 4 of N301 outputs PWM tuning signal. The 38.9MHz IF signal is
coupled to V308 (pre-amplify) and then to SAWF (Z301). After processed in the SAWF, the 38.9MHz
signal gets to pin 23 and pin 24 of OM8370. The IF circuit in OM8370 includes such unit as the AGC
amplifying circuit, 38.9MHz oscillator, PLL video demodulator, video amplifier, IF identify circuit
and AFT circuit. The demodulated signal (CVBS) comes from the pin 38 of OM8370, the sound signal
comes from the pin 44.
The internal CVBS signal needs norm identification then outputs from pin 38 of OM8370, via the
trap circuit (composed of the V351, Z351, Z354,V352 and so on) feeds back to the pin 40 of OM8370.
The RGB signal comes from pin51, Pin52, Pin53 of OM8370, and outputs to the CRT board.
The internal sound signal comes from pin 44 of OM8370 and then input to pin 1 and pin 12 of
HEF4052BP. The sound signals from RF and AV are selected in it. The selected signal is output from
Pin 3 and pin13, then input AN7522N(sound emplifier) or output from AV terminals.

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4. Horizontal and vertical circuit:
Through Synchronous separating circuit, the video signal is divided into horizontal-
Synchronizing signal and Vertical-Synchronizing signal. The horizontal-Sync pulse coming from pin
33 is transferred to the horizontal-drive transistor.
The cathode driving voltage 180V vertical drive voltage +15V and –15V are all generated from
FBT.
The vertical sawtooth waveform is generated on the pin 21 and 22, and then enters the vertical
amplifier STV9302A.
STV9302A is a 7 pins vertical deflection circuit (2 Amperes) for DC-coupled 90° or 110°
deflection systems with frame frequencies from 50 up to 120 Hz. one supply voltage for the scanning
and second voltage supply for the flyback are needed.
The vertical drive currents of OM8370 pins 21 and 22 are connected to input pins 1 and 7 of
STV9302A. The vertical scanning output is coming from pin 5 and feed back to pin 1 by R405. The
supply voltage is ±15V at pin 2 and pin 4. C406 is the pump capacitor.
5. Power supply
The IC of KA5Q0765RT is adapted in this chassis; it is the product of Fairchild. It supplies four
DC voltages, one is the +B＝110V, another is Hcc＝26V, the third is 13V (the sound drive voltage),
the fourth is +16V. The +16V can generate the +8V, +5V and +3.3V by the special generators.

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Appendix 1: IC illustration
Fig.1 OM8370 illustration
Pin1: Standby control,“1”is on,“0”is off.
Pin2: SCL.
Pin3: SDA.