Zenith C32V23 Service Manual

Also see for C32V23 - 32" Flat-Screen Integrated HDTV: Operating guide & warranty

PV154 - 923-03497 3-7 AB - SERVICINGSERVICINGSMALL SIGNAL MODULEThe AB chassis features 10 IC's for small signal processingand 5 regulators for small signal power supply. TheICM2200 CXA2150Q (0IMCRSO007A) is the video andsynchrony selector and ICM2700 is the video driver.They work together to process all video signals andsynchrony (see the block diagram), this circuit is theheart of AB chassis. The main board employs oneadditional daughter board that processes the digitalsignal for HDTV reception. This board is shielded and isconnected through CNP200A and CNP201A.Y inCb inCr inH inV inBW DRVH DRVHC PARAV DRV-V DRV+VTIMB-OSDG-OSDR-OSDFB-OSDHT-OSDSVM_OUTVPROTHP-INABL-INR-OUTG-OUTB-OUTIK-INB-PIPG-PIPR-PIPFB-PIPVideoProcessingCXA2150QSVM moduleLARGESIGNAL moduleVIDEOOUTPUT modulePIP Processor“provision”Video/Sync SelectorCXA2151QLARGE SIGNAL moduleMicro processorY awCb awCr awH sync swV sync swSD A-1, SCL-1SIF (from Tuner)SIF (from 2ndTuner)“Provision”SIF-1SIF-2AUX-L/AUX-Rfrom SwitcherADC DE-MOD Pre-proc DACH/PDACDACDACADCPre-scalePre-scaleSCARTDSPInputSelect SOUNDPROCESSORMSP4450GSource SelectSDA-1, SCL-1Audio AmpTDA 7263R Audio outSCARTOutputSelectMonitor outL monitorR monitor12S_CL12S_WS12S_DA_OUTAnalog Main BDPower Mute fromMicroprocessorL Audio outAUDIO SYSTEMThe AB chassis is offers up to five audio input sourcesand an AUX output for MONITOR through the RF Switch.The tuner delivers IF signals that are processed by U1200and U1201 saw filters. Finally the IF signal is applied toIC1203 which contains IF amplifiers and AGC circuits.AGC adjustment is manually done through R1242. ThisIC also delivers the down converter digital IF signal tothe digital board which is connected to CNP200A andCNP201A connectors. The it processes the audio andvideo signals and the audio is delivered to IC1400.The IC1400 MSP44506 (0IMCRMN012A) is the audioprocessor. It handles the ANALOG IF and decodes theanalog stereo signal and includes audio tone controls.The EZBASS circuit is for BASS and TREBLE enhancement.The following is the block diagram for this IC and theaudio system.