Fisher CA 873 Service Manual

Page 1

SERVICE MANUAL

INTEGRATED
STEREO AMPLIFIER

ff FISHER
CA-873

(EUROPE)

1 32 299 43
SPECIFICATIONS

POWER AMPLIFIER SECTION Phono Max. Input Capability 150 mV
Minimum RMS sine wave power per channel Tone Controls
within stated bandwidth at no more than stated Bassi1OOHz) :10 dB
distortion and with 8-ohm load 1 10 Watts Treblei10KHz) :10 dB
Power Bandwidth 20 Hz - 20 kHz Loudness Contour (100 Hz/1O kHz) +8 dB/+4 d8
Total Harmonic Distortion Hum 8. Noise (iHF Short Circuit, A Network)
|.M. Distortion Phono 65 dB
Speaker Damping Tape Monitor 1,2 85 dB
PREAMPLIFIER SECTION Tuner/Video/CD 85 d5
Frequency Response GENERAL

Phono (RIAA) Power Requirements (50 Hz) AC 110/220 V

Aux (20 Hz - 20 kHz)
Input Sensitivity and Impedance

Phono 2.5 mV/50 k0
150 mV/SO kn
150 mV/50 kn

Tape Monitor 1 ,2
Tuner/Video/CD

Power Consumption 510 Watts
Dimensions (WxHxD) 440x108x315mm
Weight (approx) 8.7 kg

- Specifications and design are subject to change without notice.-

REFERENCE No. WM-19678

Page 2

CABINET & CHASSIS EXPLODED VIEW

POWER AMPLIFIER ADJUSTMENT

BEFORE ADJUSTMENT
Unplug the AC power cord and set the front panel controls as follows:

Power switch to OFF position.
Set the SPEAKERS switch to the OFF position.
Set the volume level to minimum level by Pressing the VOLUME DOWN button.

IDLING CURRENT ADJUSTMENT VR501/VR502 (on the Main Amplifier P.C.Board) setting to mechanical
center position.

Connect the AC power cord and Power Switch to the ON position.

IDLING CURRENT ADJUSTMENT
This adjustment is very sensitive to changes in ambient temperature. Allow set to operate for 2 minutes
before attempting this alignment.

LEFT AMPLIFIER RIGHT AMPLIFIER

1) Connect the DC Voltmeter between Pins 19 and 21 on 1) Connect the DC Voltmeter between Pins 20 and 22 on
the Main Amplifier P.C.Board. the Main Amplifier P.C.Board.

2) Adjust the VR501 for an indication of 9mV (7mV 2) Adjust the VR502 for an indication of 9mV (7mV
~15mV) on the DC Voltmeter. ~15mV) on the DC Voltmeter.

Page 3

CABINET & CHASSIS PARTS LIST

PRODUCT SAFETY NOTICE

Each precaution in this manual should be followed during servicing, Components identified with the IEC symbol A in
the parts list and the schematic diagram designate components in which safety can be of special significance. When
replacing a component identified with A, use only the replacement parts designated, or parts with the same ratings of
resistance. wattage or voltage that are designated in the parts list in this manual
Leakage-current or resistance measurements must be made to determine that exposed parts are acceptably
insulated from the supply circuit before returning the product to the customer.

Rel.

Nit. Part No. Descrlptlon Oty N 0 Part No. Description 011!
PACKAGE 22 141-2-1219-40908 Panel Rear 1
3-9415-10300 Bag Polyethylene 1 23 141-2425941200 Bottom Cover 1
131-6300936090 Pad 1 24 141 -2-21 49-31 200 Panel Front 1
131-6-3009-36420 Pad 1 25 141-2-3119-31600 Chassis 1
131-6-3009-36700 Pad 2 26 141 -2-31 29-06600 Sub Chassis 1
131-6-3009-16350 Patching Sheet 1 27 141 -2»3159>05800 Metal Relnioroe 1
13164155941200 Serial No, Sheet 2 20 141-2-3229-62900 Plate Shield 1
141-6-1189-28502 Box Cmrugate-Exp. 1 29 141-2-4859-41200 Plate Sever 3
141 -6-1469-11700 Pad (Front) 1 30 131 >2»7104v00500 Plate Pad Switch 1
11116446941800 Pad (Rear) 1
141 -6-251 9-22290 Sheet Polyethylene 1 37 A 4-2432-00400 Power Cord 1
35 A 4-2512-25021 Power Trans 1
ACCESSORIES 40 A 4-2312-01020 Switch Slide (AC SELECTOR) [$901] 1
131-6-2719-10401 Bag Fan 1 41 46129-70724 Lamp 2
1426-4119-33420 Explanatory Booklet 1 42 405 017 7804 TR 28032014) [0515, (1516, 0546] 3
or 405 060 2504 TH 28D1975-P [0515, 0516] 2
43 405 003 4008 TR ZSA1302'0 [0517, 0515, 0545] 3
CABINET A CHASSIS or 405 031 9006 TH 2881163-P [0517,0518] 2
4237921520 Terminal Lug 2 44 141-0-1939-23331 Input PCBt Assy 1
141-2472907100 Wire Band 10 45 141-0-1939-23340 Tone P,C. B. Assy 1
131-6455911200 Serial No Sheet 1 46 141-0-1939-23351 Control PCB. Assy 1
1 13121410-35400 Cover 1 47 141-0493923360 Pin Jack PCB. Assy 1
2 131 21601 439601 Knob [Speaker Selector) 2 48 1 41 0193923370 Volume SW. PCB. Assy 1
3 131 -2-1601 413303 Knob (Power Switch) 1 49 1410-1939-23380 Balance Volume PCB. Assy 1
4 131-2-1601-93400 KnobIBalanoe) 1 50 141-0-1939-23390 LCD PCBI Assy 1
5 131-2-1601-99800 Knob Tact 3 52 141-0-1939-23411 Main AMP PCB. Assy 1
6 131-2-3202-13400 Metal Reinlorce 2 53 141-0-1939-23421 Power SW. P.C.Et Assy 1
7 131 23608-16413 Filter 1 54 141-0-1930-23430 Speaker Terminal P.C.B. Assy 1
a 1 31 -2»5205»33300 Cushion 1 55 141 -0-1 939-20450 Bias PCE Assy 2
9 --141-0-1129-29306 Cabinet Front Assy 1 56 141-0-1939-23290 Lamp PCB. Assy 1
- 141-2-1129-56903 Cabinet Front 1 56 141 -0-1 93923560 Transistor 1+5) P.c.B. Assy 1
--141-2-1449-79901 Plate Front 1
-141»2-1319-52300 Window 1 61 141-2-4219-38400 Screw, Bind Hd, Tapping-B, +M4,0X0 Sems 4
-131-2-3608-16600 Filter 1 62 131-2-4201-25201 Screw, Brazier Hd. Tapping-B. +M3V0X8 7
__141_2_1449_55013 Plate Decorate 1 63 141 24219-43300 Screw) Bind Hd. Tapping-C, +M4.0X10 4
-131-2-1601-99700 Knob (Volume) 1 64 411 002 4901 SCR PAN 2X4 6
*131-2-1601-91800 Knob (Function) 1 65 411 003 8908 SCR PAN+SW 3X6 2
-- 4-2359-78079 Connector 1? Assy 1 66 411 020 5706 SCR S-TPG BRZ 2,6)(8 10
_ 411 020 5508 SCR S-TPG BRZ 2,6X6 1 67 411 020 7700 SCH S~TPG BRZ 3X6 26
-131-2-E113-52400 Shelter 1 68 411 099 9704 SCR S»TPG BRZ 3X6 12
- 4-2352-02721 Connector 1 P Assy 1 69 411 099 9803 SCR S~TPG BRZ 3X8 11
10 -141-0-3519-26700 Mount PCBi Assy 1 70 411 020 5904 SCR S~TPG BRZ 3X10 16
-141»2-3519-84700 Mount P.c.B. 1 71 411 002 9104 $00 PAN 3X8 2
-141-2-1449-65110 Screen LCD 1 72 411 020 6004 SCR S~TPG BRZ 3X8 2
-141-2-3229v62500 Plate Shield 1
- 4-2359-79034 Connector1P Assy 1 0901 403 074 2701 CERAMIC 0.047U Z 50V 1
11 141-2-1659-35900 Knob Slide (Tone) 2 0902 403 074 2701 CERAMIC 0.047U Z 50V 1
12 141 21659-77800 Knob Push (Tapez Monitor) 1
13 1412315903300 Bracket Cover 1 NOTES:
14 131-2-4221-00600 Rivet 4 1. Parts order must contain Model Number, Part Number and
15 131-2-1410-34839 Cover Heat Sink 1 Description.
16 131-2-1801-14100 Leg 4 2 Ordering quantity of screws and resistors must be multiple of
17 131»2-4201-1 7000 Screw Ground 1 10 pcs.
18 131-2-52054 5800 Cushion 1
19 131-2-5205-35900 Cushion 1
20 131-2-6111-14200 Bushing (4N-4) 1
21 131-2-6201-38500 Heat Sink 1

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