Onkyo TA 2140 Service Manual

Page 1

ONKYO SERVICE MANUAL

STEREO CASSETTE
TAPE DECK
MODEL TA-2140

Black models

TA-2140

0M 3261

UDN, UDC, UD

120V AC, 60Hz

UG 220V AC, SOHZ

UW

120 or 220V AC, 50/60Hz

UQA, UQB

240V AC, 50Hz

SAFETY-RELATED COMPONENT WARNING

COMPONENTS IDENTIFIED BY MARK f: ON
THE SCHEMATIC DIAGRAM AND IN THE PARTS
LIST ARE CRITICAL FOR RISK OF FIRE AND
ELECTRIC SHOCK. REPLACE THESE COM-
PONENTS WITH ONKYO PARTS WHOSE PARTS
NUMBERS APPEAR AS SHOWN IN THIS MANUAL.

MAKE LEAKAGE-CURRENT OR RESISTANCE
MEASUREMENTS TO DETERMINE THAT
EXPOSED PARTS ARE ACCEPIABLY IN-
SULATED FROM THE SUPPLY CIRCUIT BEFORE
RETURNING THE APPLIANCE TO THE
CUSTOMER.

{ONKYQ
itlllllll clIMlllllllllls

Frequency Response:

S/N Ratio:

lnput Jacks:

Outputs:

Motors:
Heads:

Power Supply:
Power Consumption:
Dimensions:

SPECIFICATIONS
Track System: racks, 2-channels
Erasing System: AG erase
Tape Speed: 4.8 cm/sec (1»7/8 i.p.s.)
Wow and Flutter: 0.06% (WRMS)

2015.000Hz (Normal)
(SO-14,000Hz :GdB)
20-16.000Hz (High)
(SO-15,000HZ x3dB)
20-17,000Hz (Metal)
(SO-16.000Hz zada)
Dolby NR off: 58:18 (metal position tape)
A noise reduction ot1odB above 5kHz
and 5dB at 1kHz is possible with Dolby 8
NR. A noise reduction of 20dB at 5kHz is
possible with Dolby 0 NR.
Microphone jacks: 2
Input sensitivity: 0.6mV/600 ohms
input impedance: 2.7 kohms
Line IN: 2
Input sensitivity: SOmV
Input impedance: 50 kohms
Llne OUT: 2
Standard output level: 500mV (OdB)
Optimum load impedance: over
50 kohms
DC servo motorx 1; DC motorx 1
REC/PB: Special Hard Permalloy x 1:
Erase head: Ferrite M
AC 120V. 60Hz
20 watts
435M) x 112(H) x 262(D)mm
(171/8" x 4-3/8" x 10'3/8")

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TA-2140

Weight: 4.1 kg. (9.1 lbs.)

Specifications and external appearance are subject to change
without notice because of product improvements.

SERVICE PROCEDURES

]. Replacing the lamp
This unit used the lamp listed below.

Parts No.
210090

Circuit No.
PL901

Description
PL14V lSOmA

Caution: Before replacing the lamp. Be sure to unplug the
power supply cable.

2. Instruction resistance measurement

Connect the insulating-resistance tester between the plug of
power supply cord and chassis.

Specifications; 500V more than 10M!)

3. Replacement of power supply cord

There are two power supply cord outlets on the strainrelief.
Insert them in prescribed direction to ensure safety. AS-UC<
3 (UD<120V> model) should be inserted lengthwise and
other types of cords should be inserted horizontally.

Power Supply Cord Power Supply Cord

3
length wise Horizontal
direction direction

4. Method for removing BOTTOM BOARD
(refer to exploded view of chassis)

1. Remove top cover.

. Remove front panel.

, Remove the 2 mounting screws of the main PC board
(NAAF-2947- l ).

. Remove the 2 holders from the PC board.

. Remove the l fastening screw of the Power Switch
PC board (NAPS-2951-l ).

_ Remove the holder from the PC board.

. Remove the 4 fastening screws of the back panel and
bottom board.

. Remove the 3 fastening screws of the front bracket
and bottom board.

. Remove the ground terminal.

. Remove the bottom board by taking from the lower
direction.

5. Mechanism operation

This mechanism consists of a capstan motor, reel motor,
and solenoid, with the power assist method by means of the
capstan motor. In the operation, there are 3 conditions:
STOP, PLAY, and CUE/REV. When the position is trig-
gered by the solenoid, by means of intermittent rotation of
the gear from the flywheel, as shown in Fig. l, cyclic shift-
ing is done.

To go from STOP to PLAY, if the solenoid is pulled in
for 30ms, after about 150ms there is a shift to the PLAY
condition. From this condition, if the solenoid is again
pulled in, in that interval the condition shifts to CUE/
REV. However, to suppress heat generation in the solenoid,
the supply voltage must be reduced. If the power to the
solenoid is cut off, the head lowers, and the condition
goes to STOP. in order to have a cyclic operation as stated
above, and to know the existing condition, a play switch is
provided, and this switch is ON for PLAY and OFF for
STOP (CUE/REV) is indefinite. When power is turned
ON, the mechanism makes use of an initializer.

CUE/REV
STOP
Fig. 1

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,uPC1297CA (DOLBY HX PRO SYSTEM)

TA-2140

When the HX PRO is operation, by means of the recording

!

signal coming from the recording head, a modulating oscil-

lator voltage is applied to the absolute value detection
circuit, and by means of the recording signal level peak
detection value, the bias current is instantaneously control-

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Page 18

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TAPE MECHANISM-EXPLODED VIEW