Схема телевизора AKAI CT-1417

Формат файла: ZIP

AKAI CT 1417 UK
Electrical Adjustments / CRT Diagram / Remote Control Diagram / Ear Jack Diagram / Main Diagram
4. Fix the convergence magnets by turning the
5. Remove the DY wedges and slightly tilt the
deflection yoke horizontally and vertically toobtain the good overall convergence.
6. Fix the deflctlon yoke by wedges.7. If purity error is found, follow "PURITY
ADJUSTMENT" instructions.
I. PLEASE READ BEFORE ATTEMPTINGSERVICE1. Never disconnect any leads while receiver is
in operation.
2. Disconnect all power before attempting any
3. Do not short any portion of the circuit while
power is on.
4. For safety reasons, all parts replaced should
be identical, (for parts and part numbers seeparts list).
5. Before alignment the set must be pre-heated
for 30 minutes or more and erase magnetismthoroughly from CRT front chassis frame byerase coil.
TEST EQUIPMENT
VIF Sweep Generator
SIF Sweep Generator
DC Power Supply (14V)
Oscilloscope
Digital Multi Meter
CRT Colour Analyzer
Demagentizing Coil
Philips Pattern Generator
Frequency Counter
TANK COIL ALIGNMENT
A. PREPARATION STEP (SEE FIG.2)1. Connect OUTPUT lead of VIE Sweep
Generator between SA101 Pin 4 and ground.
2. Connect lead of FROM DET between TP106
(Pin 19 of IC101) and ground.
3. Apply a +14V DC to lead of D408.4. Apply a AGC bias (approx 6.14V) to TP104.
Slowly adjust the AGC bias voltage until thewaveform is just before saturation.
B. ALIGNMENT STEP (SEE FIG.3)
1. Adjust T105 (TANK COIL) to obtain maximumamplitude of response at 39.5MHz as in Fig.3.
IV. VIF ALIGNMENT (TUNER VIF COIL)A. PREPARATION STEP (SEE FIG.4)1. Connect the output of VIF Sweep Generator
between tuner test point TP and tuner casewith input level of 54dBpV.
2. Connect resistor (100 Ohm) between TP101
3. Connect the vertical input of the Oscilloscope
to the TP106 and ground.
4. Apply a +14V DC to lead of D408.5. Apply a AGC bias (approx 6.14V) to TP104.
B. ALIGNMENT1. Adjust AGC bias voltage slowly until the
waveform is just before saturation.
2. Adjust the vertical gain control of the Oscillo-
scope until the waveform is 10 division on thescreen.
3. Adjust the ferrete core in the tuner until the
marker 39.5MHz has maximum amplitude and35.07MHz has a difference of 1 division asshown in Fig.4.
V. AFC ALIGNMENTA. PREPARATION STEP (SEE FIG.5)1. Connect the signal output of Sweep/Marker
Generator to TUNER IF OUTPUT with asignal level of 75dBpV.
2. Connect the vertical input terminal of
Oscilloscope to TP107.
3. Apply a +14V DC to lead of D408.4. Apply a +6.14V DC to TP104.
B. ALIGNMENT STEP1. Adjust the AGC bias voltage slowly until
bottom portion of the waveform is just beforesaturation.
3. Adjust T106 (AFC COIL) for a waveform as
shown in Fig.6.
VI. SIF ALIGNMENTA. PREPARATION STEP (SEE FIG.7)1. Connect the output of SIF Sweep Generator
between TP106 and ground.
2. Connect the vertical input of Oscilloscope
between TP105 and ground.
3. Supply DC +14V to (+) lead of D408.
B. ALIGNMENT STEP1. Adjust the output of Sweep Generator until a
similar waveform is obtained (Fig.8).
2. Adjust T104 to obtain the marker 6.0MHz
rested on the horizontal line (Fig.8).NOTE: Input Level = 90dB.
VII. B+ ADJUSTMENT1. Connect the digital voltmeter to TP401.2. Adjust semi-fixed resistor VR901 until meter
reading DC 112.25V
VIII. HORIZONTAL CIRCUIT ADJUSTMENT1. Connect the frequency counter to the heater
of the CRT and ground.
2. Set the TV set to AV mode without any input
3. Adjust the VR303 until the frequency is
4. Set the TV set to TV mode and Receive
Monoscope Pattern.
5. Adjust VR302 to move the pattern horizontally
for center position.
IX. VERTICAL CIRCUIT ADJUSTMENT1. Connect the frequency counter between V-
deflection yoke and ground..
2. Set the TV to AV mode without any input
3. Adjust the V-hold VR304 until the counter
reads 44Hz
4. Set the TV set to TV mode and Receive
Monoscope Pattern.
5. Adjust V-SIZE (VR401) control to obtain a
normal picture.
X. FOCUS ADJUSTMENT1. Set Contrast control to maximum position and
Brightness control to middle position.
2. Adjust Focus control (on the FBT) to obtain a
sharpest picture on the CRT.
XI. COLOUR DEMODULATOR ALIGNMENT,DELAY LINE ALIGNMENT1. Receive Philips Pattern.2. Set Contrast control to minimum position.3. Set Colour control to maximum position.4. Connect Oscilloscope to TP301 (B-out).5. Adjust CT301 to obtain the waveform as in Fig.9.6. Adjust VR301 to obtain the waveform as in Fig.9.7. Adjust T301 to obtain the waveform as in Fig.9.
Electrical Adjustments
XII. RF AGC1. Connect a TV signal (60dB) from centre
system to the tuner.
2. A digital voltmeter is connected to the AGC
terminal of tuner (Pin 4).
3. Adjust VR101 until the voltmeter reads 4.8V.
XIII. ON SCREEN ADJUSTMENT (SEE FIG 10)1. Receive the Monoscope Pattern.2. Press the volume control.3. Adjust OSD (VR601) so that the On Screen
Display is at center position.
XIV. WHITE BALANCE ADJUSTMENT1. Receive a Monoscope Pattern picture signal.2. Turn the red, green and blue LOW LIGHT
(VR501, VR502, VR503) controls to middleposition and turn the DRIVE (VR504, VR505)control to middle position.
3. Turn the Screen control on the FBT to
minimum position.
4. Set the Sub-Brightness (VR305) control to
middle position, then set the Contrast controland Colour control to minimum position.
5. CN403 (Pin 1,2) with Join together.6. Connect volt meter between (R508) and
ground, and adjust Brightness control to thereading of DC 138V (
2V). If DC 138V cannot
be obtain, adjust the Sub-Brightness control(VR305).
7. Slowly turn the Screen control clockwise to
the point where a horizontal line just illumi-nates.
8. Adjust VR501 to get a red horizontal line on
9. Adjust VR502 to get a yellow horizontal line
10.Adjust VR503 to get a white horizontal line
11.Reset the Service Switch (S401) to "NOR-
MAL" position and turn Brightness control tomiddle position.
12.Adjust Drive (VR504, VR505) control to
obtain a uniform white picture.
XV. SUB-BRIGHTNESS ALIGNMENT1. Receive a Monoscope Pattern.2. Set controls as follows
BRIGHTNESS control........CENTER position.CONTRAST control...........CENTER position.COLOUR
control...........CENTER position.
3. Adjust SUB-BRIGHTNESS (VR305) to get
NINE step of the grey scale just illuminate inmonoscope pattern as shown in Fig 11.
XVI. COLOUR PURITY ADJUSTMENT(SEE FIG.12)BEFORE ALL ADJUSTMENT DESCRIBEDBELOW ARE ATTEMPTED, V-HOLD, H-HOLD,V-HIGH, B+ VOLTAGE AND FOCUSINGADJUSTMENT MUST BE COMPLETED.
1. Place the TV receiver facing NORTH or
2. Plug in TV receiver and turn in on.3. Operate the TV receiver over 30 minutes.
4. Fully degauss the TV receiver by using an
external degaussing coil.
5. Receive a crosshatch pattern and adjust the
static convergence, control roughly.
6. Loosen the clamp screw of the deflection
yoke and pull the deflection yoke towards you.
7. Fully turn the red and blue Drive (VR503,
VR505) controls counter-clockwise.
8. Adjust the purity magnets so that green field
is obtained at the center of the screen.
9. Slowly push the deflection yoke towards bell
of CRT and set it where a uniform green fieldis obtained.
10.Tighten the clamp screw of the deflection
XVII. CONVERGENCE ADJUSTMENT(SEE FIG.12)1. Receive a crosshatch pattern.2. Unfix the convergence magnet damper and
align red with blue dots at the center of thescreen by rotating (RB) static convergencemagnets.
3. Align Red/Blue with green dots at the center
of the screen by rotating (RB-G) staticconvergence magnet.
Remote Control
Ear Jack Diagram