Pioneer m 790 service manual

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(U) PIONEER'

TheArtofEntertainment

Service __
Manual

,, 3' ORDER NO.
. . ._. RRV 1 4 6 5
STEREO POWER AMPLIFIER
THIS MANUAL IS APPLICABLE TO THE FOLLOWING MODEL(S) AND TYPE(S).
Model
Type "-790 Power Requirement Remarks
KUXJ 0 AC120V
KCXJ O AC120V

0 This product is a systems) component.
This product does not function properly when independent; to avoid malfunctions, be sure to
connect it to the prescribed system component(s), otherwise damage may result.

CONTENTS

. SAFETY INFORMATION 2
. PACKING, EXPLODED VIEWS AND PARTS LIST ...... 3
. SCHEMATIC AND PCB CONNECTION DIAGRAMS 8
. PCB PARTS LIST .
. ADJUSTMENTS....
HOW TO CHECK M-790
. BLOCK DIAGRAM
. PANEL FACILITIES
. SPECIFICATIONS .....

wangmawma

PIONEER ELECTRONIC CORPORATION 4-1, Meguro 1-Chome, Meguro-ku, Tokyo 153. Japan

PIONEER ELECTRONICS SERVICE, INC. ROBOX 1760, Long Beach, CA 90801-1760, USA.
PIONEER ELECTRONIC [EUROPE] N.V. Haven 1087, Keetberglaan 1, 9120 Melsele, Belgium
PIONEER ELECTRONICS ASIACENTRE PTE. LTD. 501 Orchard Road. 810-00 Lane Crawford Place, Singapore 0923

© PIONEER ELECTRONIC CORPORATION 1996 T-FFB JAN. 1996 Printed in Japan

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M-790

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 II listed by the California Health and Welfare agency as a known reproductive toxlcant which
may cause birth defects or other reproductive harm (California Health a. Safety Code, Section 25249.5).

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

NOTICE
(FOR CANADIAN MODEL ONLY)

Fuse symbols {EB (last operating fuse) and/or a (slow operating fuse) on PCB indicate that replacement pans

must be of identical designation.

REMAFIOUE
(POUR MODELE CANADIEN SEULEMENT)

Les symboles de fusible JEB (fusible de type rapide) et/ou a- (fusible de type lent) sur CCI indiquent que les

pieces de remplacement doivent avoir Ia meme designation.

"(FOR USA MODEL ONLY)
1.SAFETY PRECAUTIONS

The following check should he 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 22972 or

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 60Hz outlet and turn the AC power switch on. Any
current measured must not exceed 0.5mA.

Reading should

Leakage not be above
current 0 5"A
IESIeI

Device
under

Test all
exposed metal
surfaces

Also test wrlh
plug reversed
(Using AC adapter
plug as requiredl

AC Leakage Test

equivalent between the earth ground and all exposed

ANY MEASUREMENTS NOT WITHIN THE LIMITS
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 appli7
ance have special safety related characteristics. These
are often not evident from visual inspection nor the
protection afforded by them necessarily can be ob-
tained by using replacement components rated for vol-
tage, 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 Sen/ice Manual. A subscription to. or ad»
ditional copies of, PIONEER Service Manual may be
obtained at a nominal charge from PIONEER.