Electrical Adjustments - Toshiba MV20FM3 Service Manual

Color television/video cassette recorder
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1.
BEFORE MAKING ELECTRICAL
ADJUSTMENTS
Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
CAUTION
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.
When you exchange IC and Transistor for a heat sink,
apply the silicon grease on the contact section of the
heat sink. Before applying new silicon grease, remove all
the old silicon grease. (Old grease may cause damages
to the IC and Transistor.)
On-Screen Display Adjustment
1.
Unplug the AC plug for more than 5 seconds to set the
clock to the non-setting state. Then, set the volume
level to minimum.
2.
Press the VOL. DOWN button on the set and the
Channel button (9) on the remote control simultaneously
to appear the adjustment mode on the screen as shown
in Fig. 1-1.
00 OSD
3.
Use the Channel UP/DOWN button or Channel button
(0-9) on the remote control to select the options shown
in Fig. 1-2.
4.
Press the MENU button on the remote control to end
the adjustments.
NO.
FUNCTION
00
OSD H
01
CUT OFF
02
RF AGC
03
VIF VCO
04
H VCO
05
H PHASE
06
V SIZE
07
V SHIFT
08
R DRIVE
09
B DRIVE
10
R CUT OFF
11
G CUT OFF
12
B CUT OFF

ELECTRICAL ADJUSTMENTS

TV
15
Fig. 1-1
NO.
FUNCTION
13
BRIGHTNESS
14
CONTRAST
15
COLOR
16
TINT
17
SHARPNESS
18
FM LEVEL
19
---
20
---
21
SEPARATION
22
TEST MONO
23
TEST STEREO
24
X-RAY TEST
Fig. 1-2
2. BASIC ADJUSTMENTS
(VCR SECTION)
2-1: PG SHIFTER
1.
Connect CH-1 on the oscilloscope to TP1002 and CH-2
to TP4201.
2.
Playback the alignment tape.
3.
Press and hold the Tracking-Auto button on the remote
control more than 2 seconds to set tracking to center.
4.
Press the VOL. DOWN button on the set and the
channel button (3) on the remote control simultaneously
until the indicator REC disappears. If the indicator REC
disappears, adjustment is completed.
(If the above adjustments doesn't work well:)
5.
Press the VOL. DOWN button on the set and the
channel button (3) on the remote control simultaneously
until the indicator REC disappears.
6.
When the REC indicator is blinking, press both VOL.
DOWN button on the set and the channel button (4) on
the remote control simultaneously and adjust the
Tracking +/- button until the arising to the down of Head
Switching Pulse becomes 6.5 ± 0.5H.
(Refer to Fig. 2-1-A, B)
7.
Press the Tracking Auto button.
2-2: VCO FREERUN
1.
Receive the VHF HIGH (63dB).
2.
Place the set with Aging Test for more than 10 minutes.
3.
Connect the digital voltmeter between the pin 7 of
CP602 and the pin 1 (GND) of CP602.
4.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (03) on the remote control to
select "VIF VCO".
5.
Press the VOL. UP/DOWN button on the remote control
until the digital voltmeter is 2.5V.
D3-1
CH-2
6.5H
CH-1
CH-2
CH-1
6.5H
Fig. 2-1-A
Fig. 2-1-B

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