Electrical Adjustment Instructions - Sylvania Emerson 6719DC Service Manual

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 com-
pleted.
Also, do not attempt these adjustments unless the
proper equipment is available.
Test Equipment Required
1. NTSC Pattern Generator (Color Bar W/White Win-
dow, 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: 0.001~50V/Div,
F-Range: DC~AC-60MHz
6. Frequency Counter
7. Plastic Tip Driver
How to make service remote control
unit:
1. Prepare normal remote control unit. (Part No.
NE200UD) Remove 4 screws from the back lid.
(Fig. 1-1)
2. Add J1 (Jumper Wire) to the remote control CBA.
(Fig. 1-2)
SCREW
Remote control unit (Bottom)
Remote control CBA
How 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 TV
unit.)
3. To enter the TV mode, press CH UP or CH DOWN
button on the TV unit.
4. Press "DISC MENU" button on the service remote
control unit. (Version of micro computer will display
on the CRT. (Ex: 057-001)
X-Ray Protection Test
X-Ray protection test should be done when replacing
any parts of this chassis.
1. Short test points J551 and J552 (on H.V. CBA).
2. Confirm that the main power turns off.
3. If the main power does not turn off, then replace
the following parts (D591, Q591, R592, R593,
R594 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
unit does not operate correctly.
Test point
J533
(+B)
HEAT SINK
(on H.V.
CBA)
(GND)
Tape
Note: J533(+B), HEAT SINK --- H.V. CBA
,VR2601 --- Power Supply/AV CBA
1. Connect the unit to AC Power Outlet.
2. Connect DC Volt Meter to J533(+B) and HEAT
Fig. 1-1 SINK (on H.V. CBA)(GND).
3. Adjust VR2601 so that the voltage of J533(+B)
becomes +114±0.5V DC.
Fig. 1-2
1-8-1
Adj. Point
VR2601
M. EQ.
--- DC Voltmeter
Mode Input
--- -----
Spec.
+114±0.5V DC
TD500EA