Magnavox CT202MW8, Service Manual, Page: 22 / 89

1-7-1 P7753EA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: “CBA” is abbreviation for
“Circuit Board Assembly.”
Note: Electrical adjustments are required after
replacing circuit components and certain
mechanical parts. It is important to perform
these adjustments only after all repairs and
replacements have been completed.
Also, do not attempt these adjustments unless
the proper equipment is available.
Test Equipment Required
1. NTSC Pattern Generator (Color Bar W/White
Window, Red Color, Dot Pattern, Gray Scale,
Monoscope, Multi-Burst)
2. AC Milli Voltmeter (RMS)
3. Alignment Tape (FL8A, FL8N), Blank Tape
4. DC Voltmeter
5. Oscilloscope: Dual-trace with 10:1 probe,
V-Range: 0.001~50 V/Div,
F-Range: DC~AC-60 MHz
6. Frequency Counter
7. Plastic Tip Driver
8. Color Analyzer
How to make the service remote
control unit:
1. Prepare normal remote control unit (Part No.
NE204UD or NE209UD). Remove 4 screws from
the back lid (Fig. 1).
2. Cut off pin 10 of the remote control
microprocessor and short circuit pins 10 and 17 of
the microprocessor with a jumper wire.
How to enter Service mode:
Service mode:
1. Use the service remote control unit.
2. Turn the power on. (Use main power on the TV
unit.)
3. To change TV mode, DTV mode, or DVD mode,
press [SELECT] button on the TV unit.
4. Press [DISC MENU] button on the service remote
control unit.
X-Ray Protection Test
X-Ray protection test should be done when replacing
any 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 replace
the following parts (D2591, Q2591, R2592,
R2593, R2594 and IC1201).
4. Perform steps 1 to 3 again.
1. DC 114V (+B) Adjustment
Purpose: To obtain correct operation.
Symptom of Misadjustment: The picture is dark and
the unit does not operate correctly.
Note: B), TP2504(GND) --- Sub CBA,
VR1601 --- Main CBA
1. Connect the unit to AC Power Outlet.
2. Connect DC Voltmeter to B) and
TP2504(GND).
3. Adjust VR1601 so that the voltage of B)
b114
±
1.0 V DC.
Fig. 1
Screws
Remote control unit (bottom)
Test Point Adj. Point Mode Input
B)
TP2504(GND)
VR1601 --- ---
Tape M. EQ. Spec.
--- DC Voltmeter +114
±
1.0 V DC