Memorex MT2325, Руководство по обслуживанию

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ELECTRICAL ADJUSTMENTS
1. BEFORE MAKING ELECTRICAL
ADJUSTMENTS
CAUTION
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•
•
•
Use an isolation transformer when performing any
service on this chassis.
Before removing the anode cap, discharge electricity
because it contains high voltage.
When removing a PCB or related component, after
unfastening or changing a wire, be sure to put the wire
back in its original position.
Inferior silicon grease can damage IC's and transistors.
When replacing IC's and transistors, use only specified
silicon grease (YG6260M).
Remove all old silicon before applying new silicon.
1-1:Prepare the following measurement tools for
electrical adjustments.
1. Synchro Scope
2. Digital Voltmeter
2. BASIC ADJUSTMENTS
On-Screen Display Adjustment
In the condition of NO indication on the screen.
Press both VOL. DOWN button on the set and the
Channel button (9) on the remote control for more than
2 seconds to appear the adjustment mode on the
screen as shown in Fig. 2-1.
Fig. 2-2
1. RF AGC DELAY
2. VIDEO LEVEL
3. FM LEVEL
4. OSD H
5. CUT OFF
6. X-RAY
7.
8. 0. RETURN
2-2: CUT OFF
1.
2.
3.
4.
5.
Place the set with Aging Test for more than 15 minutes.
Using the remote control, set the brightness and
contrast to normal position.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (5) on the remote control.
The Fig. 2-2 appears on the display.
Press the channel button (5) on the remote control.
Adjust the Screen Volume until a dim raster is obtained.
Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
NOTE
Use the Channel buttons (1-8) on the remote control to
select the options shown in Fig. 2-1.
Press the Channel button (0) on the remote control to
end the adjustments.
1. H/V
2. AKB
3. COLOR TEMP
4. PICTURE
5. OTHERS
6. TEST PATTERN
7. STEREO/SAP
8. (VOL TEST) 0. END
Fig. 2-1
2-1: RF AGC DELAY
1.
2.
3.
4.
5.
6.
Place the set with Aging Test for more than 15 minutes.
Receive a 70dB monoscope pattern.
Connect the digital voltmeter between the pin 2 of
CP101 and the pin 6 (GND) of CP101.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (5) on the remote control.
The Fig. 2-2 appears on the display.
Press the channel button (1) on the remote control.
Press the VOL. UP/DOWN button on the remote control
until the digital voltmeter is 2.3
±
0.05V.
D1-1
2-3: WHITE BALANCE
NOTE:
Adjust after performing adjustments in section 2-2.
1.
2.
3.
4.
Place the set with Aging Test for more than 15 minutes.
Receive the color bar pattern.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (2) on the remote control.
The Fig. 2-3 appears on the display.
Adjust the adjustment mode display of Fig. 2-3 until the
white color is looked like a white.
Fig. 2-3
1. AKB AUTO
2. R. BIAS
3. G. BIAS
4. B. BIAS
5. R. DRIVE
6. G. DRIVE
7. B. DRIVE
8. AGC AUTO 0. RETURN