Electrical Adjustments - Toshiba VTW2185 Service Manual

1. ADJUSTMENT PROCEDURE
Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
CAUTION
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 30 minutes to set the
clock to the non-setting state. (To release the Back-Up
immediately, take the short circuit between C1003 and
GND at the Power Off.) 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 for more than
2 seconds to display adjustment mode on the screen as
shown in Fig. 1-1.
01 RF AGC
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 CUT OFF
01 RF AGC
02 AGC GAIN
03 R DRIVE
04 R CUTOFF
05 G DRIVE
06 G CUTOFF
07 B DRIVE
08 H POSI
09 V POSI
10 ---
11 V SIZE
12 ---
13 VCO COARSE
14 VCO FINE
15 VCO COARSE L1
16 VCO FINE L1
17 BRIGHT CENT
18 BRIGHT MAX
19 BRIGHT MIN
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ELECTRICAL ADJUSTMENTS

TV
15
Fig. 1-1
NO. FUNCTION
20 CONTRAST CENT
21 CONTRAST MAX
22 CONTRAST MIN
23 COLOUR CENT
24 COLOUR MAX
25 COLOUR MIN
26 ---
27 SHARP
28 M R CUT OFF
29 M G CUT OFF
30 M B CUT OFF
31 H POS OSD
32 ---
33 ---
34 ---
35 CVBS OUT
36 APR THRESHOLD
37 BELL FILTER
38 BANDPASS
39 REC AGC
Fig. 1-2
2. BASIC ADJUSTMENTS
(VCR SECTION)
2-1: PG SHIFTER
1. Playback the alignment tape.
2. Press and hold the Tracking-Auto button on the remote
control more than 2 seconds to set tracking to center.
3. 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:)
4. Connect CH-1 on the oscilloscope to TP4501 and CH-2
to TP4201.
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. Stop the alignment tape.
2-2: VCO
(MONITOR TUNER)
1. Place the set with Aging Test for more than 10 minutes.
2. Connect the oscillator (39.5MHz) to TP601.
3. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (13) on the remote control to
select "VCO COARSE".
4. Press the LEFT/RIGHT button on the remote control
until the "OK" appear on the screen. If the "OK" is not
displayed, select the "-" side on the changed from "+" to
"-".
5. Press the channel button (14) to set to "VCO FINE"
mode.
6. Press the LEFT/RIGHT button on the remote control to
select the 5 step down point from the upper limit on the
"OK".
(Example: In case of the "OK" point 41, select 36.)
D3-1
CH-2
6.5H
CH-1
Fig. 2-1-A
CH-2
CH-1
6.5H
Fig. 2-1-B