Magnavox 19MDTR20 Service Manual

Also see for 19MDTR17: Features

Contents

1-7-1 T0102MCEAELECTRICAL ADJUSTMENT INSTRUCTIONSGeneral Note: “CBA” is abbreviation for“Circuit Board Assembly.”Note: Electrical adjustments are required afterreplacing circuit components and certainmechanical parts. It is important to performthese adjustments only after all repairs andreplacements have been completed.Also, do not attempt these adjustments unlessthe proper equipment is available.Test Equipment Required1. NTSC Pattern Generator (Color Bar W/WhiteWindow, Red Color, Dot Pattern, Gray Scale,Monoscope, Multi-Burst)2. AC Milli Voltmeter (RMS)3. Alignment Tape (VFMS0001H6), Blank Tape4. DC Voltmeter5. Oscilloscope: Dual-trace with 10:1 probe,V-Range: 0.001~50 V/Div,F-Range: DC~AC-60 MHz6. Frequency Counter7. Plastic Tip Driver8. Color AnalyzerHow to make service remote controlunit:1. Prepare normal remote control unit (Part No.NE206UD). Remove 4 screws from the back lid(Fig. 1-1).2. Cut off pin 10 of the remote controlmicroprocessor and short circuit pins 10 and 17 ofthe microprocessor with a jumper wireHow to Set up the Service mode:Service mode:1. Use the service remote control unit.2. Turn the power on. (Use main power on the TVunit.)3. To enter the TV mode, press [CH. o / p] buttonson the TV unit.4. Press [DISC MENU] button on the service remotecontrol unit. Version of micro computer will displayon the CRT. (Ex: 057-001)X-Ray Protection TestX-Ray protection test should be done when replacingany parts of this chassis.1. Short both ends of R2592 (on Sub CBA).2. Confirm that the main power turns off.3. If the main power does not turn off, then replacethe following parts (D2591, Q2591, R2592,R2593, R2594 and IC1201).4. Perform steps 1 to 3 again.1. DC 114V (+B) AdjustmentPurpose: To obtain correct operation.Symptom of Misadjustment: The picture is dark andunit does not operate correctly.Note: TP2501(+B), J2550(GND) --- Sub CBA,VR1601 --- Main CBA1. Connect the unit to AC Power Outlet.2. Connect DC Volt Meter to TP2501(+B) andJ2550(GND).3. Adjust VR1601 so that the voltage of TP2501(+B)becomes +114±1.0 V DC.Fig. 1-1ScrewsRemote control unit (bottom)Test Point Adj. Point Mode InputTP2501(+B)J2550(GND) VR1601 --- ---Tape M. EQ. Spec.--- DC Voltmeter +114±1.0 V DC