Onkyo TX 2500 MK2 Service Manual

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SERIAL NO. 3045

ONKYOE SERVICE MANUAL

SERVO lOCKED
IM/AM STEREO RECEIVER
MODEL TX-2500MK II

TABLE OF CONTENTS

Item Page
Specifications 2
Service notes 2
Component location 4
Exploded View 5
Alignment Procedures 6
Stringing diagram 8
Schematic diagram 9
Printed circuit board view 11
Parts list 14
Block diagram 15
Circuit description 15
Packing procedures 17

ON KYO®
AIIIIIII IIIIMPIIIIIIIIS

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SPECIFICATIONS

Amplifier section
Power Output

Total Harmonic
Distortion
1M Distortion

Damping Factor

Frequency Response

Sensitivity and
Impedance

Phono Overload
Treble Control

Bass Control

Signal to Noise Ratio

High Filter
Loudness (-30 dB)

Tuner section
Tuning Range

Usable Sensitivity

40 watts per channel, min. RMS,
at 8 ohms both channels driven,
from 20 Hz to 20 kHz, with no
more than 0.1% total harmonic
distortion.
0.1% at rated power
0.08% at 1 watt output
0.3% at rated power
0.1% at 1 watt output
40 at 8 ohms
20 ~ 30,000 Hz (:1 dB)
PHONO: 2.5 mV 50 kohms
TAPE PLAY: 150 mV 50 kohms
TAPE REC: 150 mV 3.5 kohms
(PHONO)
150 mVRMS at 1 kHz 0.1% THD.
110 dB at 10 kHz
:12 dB at 100 Hz
PHONO: 85 dB (at 10 mV input
IHF A network)
65 dB (IHF C network)
TAPE: ' 95 dB (IHF A network)
90 dB (IHF C network)
6 kHz 6 dB/oct.
+9 dB at 40 Hz
+5 dB at 20 kHz

FM:
AM:
FM mono:
FM stereo:
AM:

88 ~ 108 MHz
530 ~ 1605 kHz
11.2 dBf, 2 [1V
19.2 dBf, 5 14V
25 uV

50 dB Quieting
Sensitivity
Intermediate frequency

Capture Ratio
Image Rejection Ratio

IF Rejection Ratio

Spurious Rejection
Signal to Noise Ratio

ACA
AM Suppression Ratio
Harmonic Distortion

Frequency Response

Stereo Separation

Muting Level
Stereo Threshold
Locked Level
Timing Meter

General
Power Supply
Dimensions

Weight
Semiconductors

FM mono: 17.2 dBf, 4 V

FM stereo: 37.2 dBf, 40 V

FM: 10.7 MHz

AM: 455 kHz

FM: 2 dB

FM: 45 dB

AM: 45 dB

FM: 80 dB

AM: 30 (13

FM: 1/2 [F 80 dB

FM mono: 65 dB

FM stereo: 60 dB

AM: 40 dB

FM: 60 dB

FM: 50 dB .

FM mono: 0.2%

FM stereo: 0.4%

AM: 0.8%

FM: 30~ 15,000 Hz
+0.5, ~ 2 dB

FM: 37 dB at 1 kHz
30 dB at
100 ~ 10,000 Hz

FM: 14.7 dBf, 3 11V

FM: 14.7 dBf, 3 uV

FM: 14.7 dBf, 3 uV

Signal strength & Center tuning

AC 120 volts 60 H1130 watts
19"W x 6-5/16"H x 14-5/8"D
483mmW x 160mm}! x 371mmD
25.3 lbs. 11.5 kg.

1 FET, 30 Transistors, 8 ICs,

28 Diodes

Specifications are subject to change without notice for improvement.

SERVICE NOTES

1. REPLACEMENT OF THE AC FUSE
1) Remove four screws holding leg and bottom board.

2) Remove five screws holding bottom board and side bracket.

3) Replace the AC fuse on the power supply p.c.b.

2. REPLACEMENT OF THE SPEAKER PROTECTION FUSE

1) Remove a screw holding the cover and back panel and remove the cover.
. 2) Replace the fuse with indica14-ampere types.

SPEAKER as:
4A

3. When replacing differential amplifier or push-pull amplifier transistors, be sure that transistors of one channel have the

same hpE ratings.

4. If the TUNED lamp does not turn off when you touch the tuning knob, this may be due to strong signals generated by
a nearby MW or SW broadcasting station. In this case, adjust the frequency of oscillator coil with L201 until the

TUNED lamp turn off.