Haier 21F8D-S Service Manual - Page 22

(1) Small signal processing: super monolithic integrated circuits N204(TMPA8803CSN). and memory N901 (AT24C08). (2) Sound power amplifying: integrated circuits N701 ( TDA2611). (3) Horizontal and Vertical scan output circuits: Vertical output integrated circuits N402 (LA7840), Horizontal output transistor V411 (2SD1879), Horizontal flying back transformer T402 (JF0501-19910). (4) Switch power supply: switch transformer T501 (BCK-08A6F), power transistor V503 (2SC4236). (5) AV switch integrated circuits N203 (TC24C08). A2. Main integrated circuits: (1) TMPA8803CSN (2) TDA2611 (3) LA7840 Microprocessor Picture IF/sound IF/video processing/H and V Scan/color decoding Vertical output integrated circuits Sound power amplifying integrated circuits A3. Electrical circuit analysis 1 Microprocessor and Small signal processing: super monolithic integrated circuits TMPA8803CSN TMPA8803CSN is super large integrated circuit decoder, containing intermediate image amplifying, intermediate sound amplifying, horizontal and vertical scan, small signal processing, color decoding, hi-pressure tracing and over-load protection, I2C bus control. Information introducing functions and testing data for maintenance is listed in Table 1. Table 1 Step Function 1 BAND1 2 BAND2 3 KEY INPUT 4 DIGITAL GND 5 CPU RESET 6 CPU CLOCK 7 CPU ClOCK 8 TEST 9 +5 VCC C1ir0cuit EGxNpDlanation 11 SIGNAL GND 12 HORIZONTAL SYNC SIGNAL INPUT 13 HORIZONTAL RETURN PULSE SIGNAL INPUT CHARACTER HORIZONTAL LOCATION 14 HORIZONTAL AGC 15 VERTICAL SIGNAL PRODUCE Working Voltage (V) 0 1.8 5 0 5 2.3 2.0 0 5 0 0 1 1.7 Ground Resistance (R) Positive (Ω) Negative (Ω) 600 5000 600 5000 600 15000 0 0 600 10000 600 1000 600 15000 0 0 400 4500 0 0 0 0 750 150 500 550 6.3 750 1400 4.3 750 1500 22