Akai CT3216 Service Manual

SERVICE MANUAL

Model:

CT3216

Safety Instructions
Features & Specifications
Block Diagram
Circuit Diagram
Disassembly
Pin Descriptions

Exploded View Diagram

Spare Part List

This manual is the latest at the time of printing, and does not
include the modification which may be made after the printing,
by the constant improvement of product.

IMPORTANT SERVICE SAFETY INFORMATION

Operating the receiver outside of its cabinet or with its back removed involves a shock hazard.
Work on these models should only be performed by those who are thoroughly familiar with precautions
necessary when working on high voltage equipment.

Exercise care when servicing this chassis with power applied. Many B plus and high voltage RF
terminals are exposed which, if carelessly contacted, can cause serious shock or result in damage to the
chassis. Maintain interconnecting ground lead connections between chassis, escutcheon, picture tube dag
and tuner when operating chassis.

These receivers have a “polarized” AC line cord. The AC plug is designed to fit into standard AC
outlets in one direction only. The wide blade connects to the “ground side” and the narrow blade
connects to the hot “side” of the AC line. This assures that the TV receiver is properly grounded to the
house wiring. If an extension cord must be used, make sure it is of the “polarized” type.

Since the chassis of this receive is connected to one side of the AC supply during operation,
service should not be attempted by anyone not familiar with the precautions necessary when working on
these types of equipment.

When it is necessary to make measurements or tests with AC power applied to the receiver chassis,
an Isolation Transformer must be used as a safety precaution and to prevent possible damage to
transistors. The Isolation Transformer should be connected between the TV line cord plug and the AC
power outlet.

Certain High voltage (HV) maybe cause X-ray radiation. Receivers should not be operated with
HV levels exceeding the specified rating for their chassis type. Higher voltage may also increase the
possibility of failure in the HV supply.

It is important to maintain specified values of all components in the horizontal and high voltage
circuits and anywhere else in the receive that could cause a rise in high voltage, or operating supply
voltages. No changes should be made the original design of the receiver.

Components shown in the shaded areas on the schematic diagram and/or identified by in the
replacement parts list should be replaced only with exact factory recommended replacement parts. The
use of unauthorized substitute parts man creats may create shock, fire, X-ray radiation, or other hazards.

To determine the presence of high voltage, use an accurate high impedance HV meter connected
between the second anode lead and he CRT dag grounding device. When servicing the High Voltage
System remove static charges from it by connecting a 10K Ohm resistor in series Wan insulated
wire(such as test probe) between the picture tube dag and 2
disconnected from AC supply).

The picture tube use in this receiver employ integral implosion protection. Replace with a tube of
the same type number for continued safety. Do not lift picture tube by the neck. Handle the picture tube
only when wearing shatterproof goggles and after discharging the high voltage completely, Keep others
without shatter proof goggles away.

Before returning the receiver to the user, perform the following safety checks:

1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged
between the chassis and other metal parts in the receiver.

2. Replace all protective devices such as non-metallic control knobs, insulating fishpapers, cabinet
backs, adjustment and compartment covers of shiedls, isolation resistor-capacitor networks,
mechanical insulators etc.

nd

anode lead(Have AC line cord

3. To be sure that not shock hazard exists, a check for the presence of leakage current should be
made at each exposed metal part having a return path to the chassis (antenna, cabinet metal,
screw heads knobs and/or shafts, escutcheon, etc.) in the following manner.

Plug the AC line cord directly into a 120V, AC receptacle. (Do not use an Isolation Transformer
during these checks.) All checks must be repeated with the AC line cord plug connection reversed. (If
necessary, a nonpolarized adapter plug must be used only for the purpose of completing these checks.)

If available, measure current using an accurate leakage current tester. Any reading of 0.35mA or
more is excessive and indicates a potential shock hazard which must be corrected before returning the
receiver to owner.

If a reliable leakage current tester is not available, this allernate method of measurement should be
used. Using two clip leads, connect a 1500 Ohm, 10 watt resistor paralleled by a 0.15uF capacitor in
series with a known earth ground, such as a water pipe or conduit and the metal part to be checked. Use
a VTVM or VOM with 1000 Ohms per Volt, or higher, sensitivity to measure this AC voltage drop
across the resistor,. Any reading of 0.35 volt RMS of more is excessive and indicates potential shock
hazard which must be corrected before returning he receiver to the owner.

ALIGNMENT PROCEDURES

PLEASE READ BEFORE ATTEMPTING SERVICE

1. Use an Isolation Transformer when performing any service on this chassis.

2. Never disconnect any leads while receiver is in operation.

3. Disconnect all power before attempting an repairs.

4. Do not short any porsition of the circuit while the power is on.

5. For safety reasons, replacing any components should be according with identical replacement
parts (SEE PARTS LIST).

6. Before testing, warm up the TV for at least 30 minutes and demagnetize the CRT with an
external degaussing coil.

7. When removing a PCB or related component, after unfastening or changing a wire, be sure to
put the wire back in its original position.

8. Inferior silicon grease can damage IC’s and transistors. When replacing IC’s and transistors, use
only specified silicon grease,. Remove all old silicon when applying new silicon.

9. Before removing the anode cap, discharge eiecticity because it contains high voltage.

FUNCTION AND SPECIFICATION

TUBE/POWER SUPPLY

TUBE TYPE NF
SIZE 32''

ASPECT RATIO

POWER SUPPLY

MAIN POWER SWITCH

TUNER

BUILT-IN FS TUNER YES
# OF CHANNEL/PROGRAM 181 CH
COLOR SYSTEM NTSC
SOUND SYSTEM M
AV NTSC 3.58/4.43 AV NTSC 3.58

PICTURE

COMB FILTER 2LINE
TINT, COLOR, BRIGHTNESS, CONTRAST AND SHARPNESS CONTROL YES
USER SELECTABLE PICTURE CONTROL(NORMAL,BRIGHT,USER,SOFT) YES
USER SELECTABLE 3-STAGE COLOR TEMPERATURE CONTROLS YES
OSD LANGUAGE

SOUND

STEREO/MONO MTS/SAP
AV STEREO YES
SURROUND YES
TONE CONTROL(BASS/TREBLE/BALANCE) YES
USER SELECTABLE SOUND CONTROL YES
SPEAKER QUANTITY 2
AUDIO OUTPUT POWER 4W×2

USER CONVENIENCE

FULL FUNCTION REMOTE CONTROL YES
CCD YES
V-CHIP YES
CHILD LOCK YES
SLEEP TIMER YES
RECALL YES
QUICK VIEW YES

CONNECTORS

CABLE/ANTENNA INPUT 1 REAR
AV INPUT 2 REAR,1SIDE
S-VIDEO INPUT 1 REAR
COMPONENT VIDEO INPUT (YCbCr) 1 REAR
AV OUTPUT 1 REAR(Audio)
HEADPHONE OUTPUT YES

4∶3

~120V，60Hz

SOFT

SWITCH

ENG，FR，SPA

Block diagram

TUNER

SAW

V OUT

TDA8177F

NTSC M/N

UOC

TDA9378

H OUT

RGB
OUT

MTS/SAP

TDA9850

TRAP

AUDIO terminal

R/L1 R/L2 R/LO

AUDIO PRO
TDA9859

VEDIO SWITCH

TC4052

VO V1 V2 Y/C

VEDIO terminal

CRT

AUDIO POWER

TDA2616

COMB FILER
TDA9183

5V -12V 12V 18V 45V 135V

TDA16846