Service manualCHASSIS 2112-Series EC7-A
INDEX
1. SAFETY INSTRUCTIONS..................................................................................................................................... 3
1.1 WARNING. ........................................................................................................................................................ 3
1.2 PRECAUTIONS AGAINST X-RAYS. ....................................................................................................................... 3
1.3 RECOMMENDATIONS TO PROTECT OUR ENVIRONMENT......................................................................................... 3
1.4 SAFETY AND EMC (ELECTROMAGNETIC COMPATIBILITY). ................................................................................... 3
2. TECHNICAL CHARATERISTICS. ........................................................................................................................ 4
3. BLOCK DIAGRAM................................................................................................................................................ 5
3.1 INTEGRATED CIRCUITS....................................................................................................................................... 6
4. DETAILED DESCRIPTION IN BLOCKS .............................................................................................................. 6
4.1 POWER SUPPLY. ............................................................................................................................................... 6
4.1.1 Switched Mode Power Supply (SMPS).....................................................................................................6
4.1.1.1IC800 controller start-up..................................................................................................................... 6
4.1.2 Normal functioning ("on")..........................................................................................................................6
4.1.2.1Duty cycle........................................................................................................................................... 6
4.1.2.2Regulation. ......................................................................................................................................... 6
4.1.3 "Stand-by".................................................................................................................................................7
4.1.4 ?+8v? and ?+5v? regulators........................................................................................................................7
4.1.4.1Configuration...................................................................................................................................... 7
4.1.4.2?stand-by? / ?ON? control .................................................................................................................... 7
4.1.4.3Regulator output short circuit protection. ........................................................................................... 7
4.1.4.4Mains switch off detection.................................................................................................................. 7
4.1.4.5Power supply signals and micro signals interrelation......................................................................... 8
4.2 TELETEXT AND MICROPROCESSOR. .................................................................................................................... 8
4.2.1 Ports description.......................................................................................................................................8
4.2.2 Supply.......................................................................................................................................................9
4.2.3 Oscillator...................................................................................................................................................9
4.2.4 Reset........................................................................................................................................................9
4.2.5 RGB output, character generator..............................................................................................................9
4.2.5.1Character generator synchronism...................................................................................................... 9
4.2.5.2RGB output voltage............................................................................................................................ 9
4.2.6 Teletext (only for ST92195 version)..........................................................................................................9
4.2.6.1Non-interlaced.................................................................................................................................. 10
4.2.7 -PD signal..............................................................................................................................................10
4.2.8 ON signal................................................................................................................................................10
4.2.9 Radio control signals..............................................................................................................................10
4.2.10SC signal.............................................................................................................................................10
4.2.11-SUP_FAIL signal...............................................................................................................................10
4.2.12-AM/SCART signal..............................................................................................................................10
4.2.13-LP/L signal.........................................................................................................................................10
4.2.14-AM/FM signal.....................................................................................................................................10
4.2.15-DEFL_FAIL signal.............................................................................................................................10
4.2.16I2C bus and peripherics connected to (SDA y SCL)...........................................................................10
4.2.17CF1 and CF2 signals...........................................................................................................................10
4.2.18Tuning control signals (-AGC_LS, -LB, -MB, -HB, VTUNE)................................................................10
4.2.19BEEP signal.........................................................................................................................................11
4.2.20WIDTH signal......................................................................................................................................11
4.2.21MUTE signal........................................................................................................................................11
4.2.22LED signal...........................................................................................................................................11
4.2.23Customer instructions reception (IR and KEY signals).......................................................................11
4.3 HORIZONTAL DEFLECTION................................................................................................................................11
4.3.1 Driver stage............................................................................................................................................11
4.3.1.1Driver stage power. .......................................................................................................................... 11
4.3.1.2Driver stage start-up......................................................................................................................... 11
4.3.2 Line stage...............................................................................................................................................11
4.3.3 Width adjustment....................................................................................................................................12
4.3.4 H_FLY&SYNC signal generation............................................................................................................12
4.3.5 Recovered line voltages.........................................................................................................................12
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