Pioneer vsx 79 service manual

Page 1

(U) PIONEER?

SerVice
Manual

AUDIONIDEO STEREO RECEIVER

VSX-D704S

VSX-79

THIS MANUAL IS APPLICABLE TO THE FOLLOWING MODELISI AND TYPEISI.

ORDER NO.
RRV1 237

O The above illuskrfllxou shows VSX-D7MS.

Model
. The voltage can be convened by the
Type VSX-D704S VSX-79 Power Requnement following method.
KU O - AC120V -
KC 0 - AC120V -
SD O - AC1 10V/120-127V/220V/240V With the voltage selector
KU/CA -- O AC120V
CONTENTS
1_ SAFETY INFORMATION ........................ 2 7_ ADJUSTMENTS .................................
2. EXPLODED VIEWS, PACKING AND 8. IC INFORMATION ~
PARTS LIST ......................................... 3 9. FL INFORMATION
3. SCHEMATIC AND PCB CONNECTION 10. BLOCK DIAGRAM
DIAGRAMS """""""""""""""""""""""""""" 11 11. FOR VSX-D704S/KC, SD AND
4. PCB PARTS LIST ~- 51 VSX-79/KU/CA ---------------------------- 69
5. DISASSEMBLY ---------- ~ 58 12. PANEL FACILITIES --
6. PCB ASSY DIAGNOSIS ---------------------- 59 13. SPECIFICATIONS

PIONEER ELECTRONIC CORPORATION

4-1. Meguro 1»Chome, Meguro-ku. Tokyo 153, Japan

PIONEER ELECTRONICS SERVISE INC. FD. Box 1760. Long Beach. California 90801. USA.

PIONEER ELECTRONICS OF CANADA, INC.
PIONEER ELECTRONIC [EUROPE] N.V .

300 Allstate Parkway Mavkham. Omario LSR 0P2. Canada
Haven 1087 Keelberglaan 1, 9120 Melsele. Belgium

PIONEER ELECTRONICS AUSTRALIA PTV. LTD. 178.1 B4 Boundary Road. Braeside. Victoria 3195. Australia, TEL: [03] 580-9911
@ PIONEER ELECTRONIC CORPORATION 1995 1mm; M AR, 1995 Primed in Japan

Page 2

VSX-D704S, VSX-79

1. SAFETY INFORMATION

This service manual is intended for qualified service technicians; it is not meant for the casual
do-it-yourselfer. Qualified technicians have the necessary test equipment and tools, and have been
trained to properly and safely repair complex products such as those covered by this manual.
Improperly performed repairs can adversely affect the safety and reliability of the product and may void
the warranty. If you are not qualified to perform the repair of this product properly and safely, you
should not risk trying to do so and refer the repair to a qualified service technician.

WARNING

Lead in solder used in this product is listed by the California Health and Welfare agency as a known reproductive toxicant which
may cause birth defects or other reproductive harm (California Health a Safety Code, Section 25249.5).

when servicing or handling circuit boards and other components which contain lead in solder. avoid unprotected skin contact with
the solder. Also, when soldering do not inhale any smoke or fumes produced.

NOTICE

(FOR CANADIAN MODEL ONLY)

Fuse symbols EB (fast operating fuse) and/or a (slow operating fuse) on PCB indicate that replacement parts
must be of identical designation.

REMARQUE

(POUR MODELE CANADIEN SEULEMENT)

Les symboles de fusibleEEl- (fusible de type rapide) et/ou EE- (fusible de type lent) sur CCI indiquent que les
pieces de remplacement doivent avcir la meme designation.

- (FOR USA MODEL ONLY)

1. SAFETY PRECAUTIONS ANY MEASUREMENTS NOT WITHIN THE LIMITS

The following check should be performed for the
continued protection of the customer and service
technician.

LEAKAGE CURRENT CHECK

Measure leakage current to a known earth ground
(water pipe. conduit, etc.) by connecting a leakage
current tester such as Simpson Model 229-2 or
equivalent between the earth ground and all exposed
metal parts of the appliance (input/output terminals,
screwheads, metal overlays, control shaft, etc.). Plug
the Ac line cord of the appliance directly into a 120V
AC 50 Hz outlet and turn the AC power switch on. Any
current measured must not exceed 0.5 mA.

Reading should
not be above
Leakage 0.5 mA

. current

Devrce tester

under
test

Test all exposed
metal suilaces

Also lest with plug
reversed (Using
AC ndavrer plug
as required)

©vft

_ Earth ground

AC Leakage Test

OUTLINED ABOVE ARE INDICATIVE OF A PO-
TENTIAL SHOCK HAZARD AND MUST BE COR-
RECTED BEFORE RETURNING THE APPLIANCE
TO THE CUSTOMER.

2. PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in the appli-
ance have special safety related characteristics. These
are olten not evident from visual inspection nor the
protection afforded by them necessarily can be ob-
tained by using replacement components rated for
voltage, wattage , etc. Replacement parts which have
these special safety characteristics are identified in
this Service Manual.

Electrical components having such features are

identified by marking with a A on the schematics and
on the parts list in this Service Manual.
The use of a substitute replacement component which
dose not have the same safety characteristics as the
PIONEER recommended replacement one, shown in
the parts list in this Service Manual, may create shock,
fire, or other hazards.

Product Safety is continuously under review and
new instructions are issued from time to time. For
the latest information, always consult the current
PIONEER Service Manual. Asubscription to, or ad-
ditional copies of, PIONEER Service Manual may be
obtained at a nominal charge from PIONEER.