Zenith R50V26 Service Manual

Also see for R50V26: Operating guide

Contents

Zenith R50V26 Service Manual Manual pdf 37 page image

CIRCUIT DESCRIPTIONSPV154 - 923-03506 3-13 ZP26/28 - SERVICINGin the EEPROM, such as the window for Closed Captiondetection.Data and Clock lines are SDA1 from pin (2) of theMicroprocessor to pin (5) of the EEPROM and SCL2from pin (3) of the Microprocessor to pin (6) of theEEPROM. Data travels in both directions on the Dataline.FLEX CONVERTER UC01The projection television is capable of displaying NTSCas well as ATSC (DTV) including HD (High Definition).The Flex Converter is responsible for receiving anyvideo input and converting it to 33.75 Khz output.This output is controlled by sync and by the customer’smenu and how it is set up. The set up can be 4X3 or16X9 for DTV, or letterbox. This set also has somethingcalled “Through Mode”. This bypasses the FlexConverter completely and inputs the 1080i signaldirectly to the Rainforest IC. The Rainforest IC thenoutputs the signal directly. The Flex Converter cantake any NTSC, S-In, Component, NTSC or Progressive,Interlaced, 480I, 720P, 1080i signal.Control for the Flex Converter is Clock, Data and Enablelines. Clock, Data and Enable lines for the Flex Converterare output from the Microprocessor at pins (45) Dataand (46) FCENABLE. The FCENABLE line is routedthrough the PFC1 connector pin 12 and the FCDATAline is routed through the PFC1 connector pin 11.The Clock line must be routed through the Level ShiftIC I004 to be brought up to 5V. The Microprocessoroutput for Clock is pin 58, it arrives at I004 at pins(3) Clock and is output at pins (17). It arrives at theFlex Converter through the PFC1 connector pin 10.DAC1 I006This Digital to Analog converter acts as an extension ofthe Microprocessor. Sometimes called an Expansion IC.The purpose of this IC is to reduce the number of pins,(fan out) of the Main Microprocessor I001. The MainMicroprocessor sends Clock and Data via I 2 C bus to theDAC1 IC. The output from the Microprocessor is pin (2)SDA1 and (3) SCL1 which arrives at the DAC1 IC I006 atpins (5 and 6) respectively.DAC3 I007This Digital to Analog converter acts as an extension ofthe Microprocessor. Sometimes called an Expansion IC.The purpose of this IC is to reduce the number of pins,(fan out) of the Main Microprocessor I001. The MainMicroprocessor sends Clock and Data via I 2 C bus to theDAC3 IC. The output from the Microprocessor is pin (2(SDA1) and 3 (SCL1) which arrives at the DAC3 IC atpins 5 and 6 respectively.LEVEL SHIFT I004The Microprocessor operates at 3.3Vdc. Most of the Cir-cuits controlled by the Microprocessor operate at 5Vdc.The Level Shift IC steps up the DC voltage to accommo-date.• Pin 4 outputs a Clock, used by the Flex Converter• Pin 11 outputs Error Mute signal (ERRMUTE), usedto mute the Out to Hi-Fi jacks on the SRS PWB.• Pin 13 outputs a Front Speaker Off signal (FSPOFF),used to turn off the internal speakers.3D Y/C I301(IC mounted directly on the Signal PWB)The 3D Y/C IC is a Luminance/Chrominance separator, aswell as a 3D adder. Separation takes place digitally. Us-ing advanced separation technology, this module sepa-rates using multiple lines and doesn’t produce dot pat-tern interference or dot crawl. The 3D effect is a processof adding additional emphasis signals to the Luminanceand Chrominance. These signals relate specifically totransitions. Transitions are the point where the signalgoes from dark to light or vice versa. The 3D adds alittle more black before the transition goes to whiteand a little more white just before it gets to white. Italso adds a little more white just before it goes darkPIN DESC FUNCTION1 BusyReceives Busy from DCU stopping Microprocessorfrom responding to Remote commands.2 ST DetReceives the Low from the Main Tuner indicatingStereo signal received.3 MTSPlaces the Main Tuner into MTS mode if Stereo MTSDetected by Microprocessor4 F Mono Places the Main Tuner into Forced MONO mode5 AntSwitches the antenna block into Antenna A orAntenna B when selected.6 Cut OffIn Service Mode, if Set Up is selected, outputs Highto collapse Vertical circuit and inhibit Vert. SweepLoss Detection7 Magic Sw Places the Unit into HD Focus Mode.8 Gnd Ground9 D SizeDuring HD Focus and Sensor Initialize, the H and VSize has to be increased slightly for Sensor strikingpurposes.10 SAP DetReceives the Low from the Main Tuner indicating SAPsignal received.11 Gnd Ground Not Used12 Gnd Ground Not Used13 STBY 5V Standby +5 Volt input.14 SDA1 Serial Data from Microprocessor15 SCL1 Serial Clock from Microprocessor16 SBY +5V Vcc SBY +5VDAC1 I006 Pin DescriptionsNOTE: Pin 1 Busy and Pin 9 D Size works as a tri-data-level-input.The Digital Convergence Module is active during Service Adjustment(DCAM), HD Focus and/or Sensor Initialize.