Onkyo TX 31 Service Manual

Page 1

TX-31

SERIAL NO. 3124

ONKYOn SERVICE MANUAL

SERVO LOCKED
FMIAM STEREO RECEIVER
MODEL TX-31

TABLE OF CONTENTS

Item Page

Specifications 2
Precaution 2
Special modes operation 3
Alignment procedures 3
Block diagram 6
Block diagram of 1C 7
Stringing diagram 8
Disassembling procedures 8
Packing View 9

Exploded View 10
Parts list 11
Printed circuit board view from component side 13
Printed circuit board-parts list 14
Schematic diagram 19

ONKYOD
Alllllll BIIMPIINENISJ

Page 2

SPECIFICATIONS

AMPLIFIER SECTION
Output Power:

Total Harmonic Distortion:

IM Distortion:

Damping Factor:
Frequency Response:
RIAA Deviation:
Sensitivity & impedance:

Phono Overload:

Signal-to-Noise Ratio:

Tone Controls:

Loudness (- 30 dB):

TUNER SECTION

FM :
Tuning Range:
Usable Sensitivity:

50 dB Quieting Sensitivity:
Capture Ratio:
image Rejection Ratio:

Spurious Rejection Ratio:
IF Rejection Ratio:

PRECAUTION

Replacing the fuses

30 watts per channel, min. RMS, at
8 9 both channels driven, from

20 Hz to 20,000 Hz, with no more
than 0.06% total harmonic distortion.
006% at rated power

006% at 1 watt output

0.1% at rated power

0.06% at 1 watt output

35 at 8 n

20 Hz 7 30,000 Hz {:1 dB)

20 Hz # 20,000 Hz (: 0,8 dB)

Phone: 25 mV, 50 km
Tape Play: 150 mV, 50 kn
Tape Rec: 150 mV, 3.5 km (PH)

110 mV R.M.S. at 1 kHz, 0.06%
T.H.D.

Phono: 85 dB (at 10 mV input
A weighted)
75 dB (IHF A-202)
Tape: 95 dB (A weighted)
80 dB (IHF A-202)
Bass: tlZdBat lOOHz
Treble : 10 dB at 10 kHz

+9 dB at 40 Hz
+5 dB at 20 kHz

87.5 7108Ml-lz

Mono: 12.0 dBf, 2.2 1.4V
Stereo: 19.2 dBf, 5 [JV
Mono: 18.3 dBf, 4.5 11V
Stereo: 39.2 dBf, 50 11V
1.5 dB

45 dB

80 dB

80 (113

For continued protection against fire hazard, replace only with
same type and same rating fuse.

1 Speaker protection fuse

The speaker protection fuse is located on the back panel.
Remove the screw holding the fuse cover and fuse case with the

screwdriver.
Rating : 4A (SS~2)
4A-T

RN. 252059 (D model)
P.N. 252014 (W model)

SignaHO-Noise Ratio:
Alternate Channel Att.:

AM Suppression Ratio:
Harmonic Distortion:

Frequency Response:
Muting Level:

Stereo Threshold:
Servo Lock Level:

AM:

Tuning Range:

Usable Sensitivity:
Image Rejection Ratio:
IF Rejection Ratio:
Harmonic Distortion:

GENERAL
Power Supply:

Outputs:

Inputs:

Antennas:

Semiconductors:
Dimensions (WxHxD):

Weight:

Mono: 71 dB
Stereo: 66 dB
55 dB

50 dB

M0110: 0.2%
Stereo: 04%

30 Hz 715000 Hz (21.5 dB)
40 dB at 1 kHz
30 as at 100 Hz , 10,000 Hz
17.2 «131.4 w
17.2 dBf, 4 11v
17.2 dBf. 4 av

525 - 1,620 kHz
30 AN

40 dB

30 dB

0.8%

AC 120V, 60Hz (D model)

AC 120/220V, 50/60H2 (W model)
Speaker A F. B, Phones, Tape Rec
Out 1 Sr 2. AC Outlet

(unswilched x 1, switched x 1) (Only
D model)

Phono. Tape Play 1 & 2,

FM and AM Antennas

FM: 300 ohms balanced and

75 ohms unbalanced
built-in loop antenna and
external terminal

1 FET. 14 transistors, 10 le, 31
diodes

418 x 112 x 391mm

16-1/2" X 4-1/2" x 15-3/8"

8.5kg (18.7Ibs.)

AM:

Page 7

STK-3062 (Differential and drive ampli.) STK-005011 (Power ampli.)

a? Q: a? :4. Q on

1.:z?*e
l

. r; i
54nd) 700C!) to no

STRINGING DIAGRAM

yo

1. Close the variable capacitor complete and tie the stringing to the spring of the drum.

2. Thread the stringing in the direction of arrow from 1 to 3 and wind the stringing three turns around the tuning shaft counter
clockwise.

3. Thread the stringing to 5.

4. Wind the stringing ll/Z turns around the dial drum.

DISASSEMBLING PROCEDURES

1. Top Cover 3. Tone control indicator lamp
Remove the four screws holding the top cover and side Remove the top cover and front panel.
bracket. Remove the five screws holding the holder and front
Remove a screws holding the mp cover and back panel. bracket. (see Page 9)

2. From Panel
Remove the lop cover.
Remove the Bass and Treble knobs.
Remove the five screws holding the front panel and front
bracket.
Remove the signal indicator lamp pc board from lamp
holder.