IBM PCjr Owner's manual

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Personal Computer PCy'r
Hardware Reference
Library
Hardware
Maintenance
and Service
1502263

Personal Computer PCyr
Hardware Reference
Library
Hardware
Maintenance
and Service

First Edition (September 1983)
Changes are periodically made to the information herein; these
changes will be incorporated in new editions of this publication.
Products are not stocked at the address below. Requests for
copies of this product and for technical information about the _
system should be made to your authorized IBM Personal
Computer dealer.
A Reader's Comment Form is provided at the back of this
publication. If this
form has been removed, address comments to
IBM Corporation, Personal Computer, P.O. Box 1328-C, Boca
Raton, Florida 33432. IBM may use or distribute any of the
information you supply in any way it believes appropriate without
incurring
any obligations whatever.
©Copyright International Business Machines Corporation 1983

FEDERAL COMMUNICATIONS
COMMISSION RADIO FREQUENCY
INTERFERENCE STATEMENT
Warning: This equipment has been certified to
comply with the limits for aClass Bcomputing
device, pursuant to Subpart J of Part 15 of FCC
rules. Only peripherals (computer input/output
devices, terminals, printers, etc.) certified to comply
with the Class Blimits may be attached to this
computer. Operation with non-certified peripherals
is likely to result in interference to radio and TV
reception.
INSTRUCTIONS TO USER
This equipment generates and uses radio frequency
energy and if not installed and used properly, i.e., in
strict accordance with the operating instructions,
reference manuals, and the service manual, may cause
interference to radio or television reception. It has been
tested and found to comply with the limits for aClass B
computing device
pursuant to Subpart J of Part 15 of
FCC Rules, which are designed to provide reasonable
protection against such interference when operated in a
residential installation.

If this equipment does cause interference to radio or
television reception, which can be determined by
turning the equipment off and on, the user is
encouraged to try to correct the interference by one or
more of the following measures:
•
Reorient the receiving antenna.
• Relocate the equipment with respect to the receiver.
• Move the equipment away from the receiver.
• Plug the equipment into a different outlet so that
equipment and receiver are on different branch
circuits.
• Ensure that side option mounting screws,
attachment connector screws, and ground wires are
tightly secured.
• If peripherals not offered by IBM are used with this
equipment, it is suggested that you use shielded,
grounded cables with in-line filters, if necessary.
If necessary, consult your dealer service representative
for additional suggestions.
The manufacturer is not responsible for any radio or
TV interference caused by unauthorized modifications
to this equipment. It is the responsibility of the user to
correct such interference.
CAUTION
This product is equipped with a UL listed and
CSA-ceitified plug for the user's safety. It is to be
used in conjunction with aproperly grounded 115 ^
Vac receptacle to avoid electrical shock. ' ^

Preface
The Hardware Maintenance and Servicemanual helps
you isolate and repair failures of the IBM PCyr. You
should be trained to service the IBM PC/r and be
famihar with the Triplett Model 310 Multimeter^ (or
equivalent).
This manual consists of six sections:
Section 1, "Introduction," provides acapsule
description of the IBM PCyr and its options.
Section 2, "Introduction to Diagnostics," hsts the items
you
need to perform the IBM PCyrdiagnostics.
Detailed instructions explaining
how to perform the
advanced power-on self-test (POST) and other
advanced tests are included here.
Section 3, "Problem Isolation Charts," contains the
start point for IBM PCyr diagnostics. This section
assumes you have read Section 2 and know how to
perform advanced tests.
Section 4, "Removal/Replacementand Adjustments,"
provides all the information needed to complete arepair
after the failing field replaceable unit (FRU) is
identified in Section 3.
Section 5, "Locations," assists you in finding a part or
FRU in the IBM PCyr.
1Manufactured by Triplett Corporation, Bluffton, Ohio 45817
m

IV
Section 6, "Parts Catalog," contains part numbers for
the IBM PCyr parts and FRUs.
Complete operating instructions for the IBM PCyr are
in the Guide to Operations, IBM part numbers 1502291
and 1502292. Detailed hardware design and interface
information are in the Technical Reference, IBM part
number 1502293.

Contents
Section 1. Introduction 1-1
Description 1-3
Features 1-3
Options 1-3
Section 2. Introduction to Diagnostics 2-1
Required Items for Diagnostics 2-3
How to Perform Advanced POST 2-4
How to Perform Advanced Tests 2-8
Section 3. Problem Isolation Charts 3-1
Start 3-000-1
Undetermined Problem 3-010-1
Power 3-020-1
Memory 3-200-1
Keyboard 3-300-1
Display 3-500-1
Diskette Drive 3-600-1
Light Pen 3-800-1
Cartridge 3-810-1
Sound 3-820-1
Internal Modem 3-830-1
RS232 3-840-1
Compact Printer 3-850-1
Parallel Printer Attachment 3-900-1
Joystick 3-1300-1
Graphics Printer 3-1400-1
Section 4. Removal Replacement and Adjustments 4-1
How to Use this Section 4-5
Power 4-020-1
Power Board Removal 020 4-020-1

VI
Power Board Replacement 025 ... 4-020-3
System Unit 4-100-1
System Unit Top Cover Removal
100 4-100-1
System Unit Top Cover
Replacement 105 4-100-2
Side Cover Removal 110 4-100-3
Side Cover Replacement 115 4-100-4
System Board Removal 120 4-100-5
System Board Replacement 125 .. 4-100-9
Memory 4-200-1
64KB Memory and Display
Expansion Removal 200 4-200-1
64KB Memory and Display
Expansion Replacement 205 .... 4-200-2
Keyboard 4-300-1
Infra-Red Receiver Removal 300 .4-300-1
Infra-Red Receiver Replacement
305 4-300-2
Keyboard Battery Replacement 310 4-300-3
Display 4-500-1
IBM Color Display Removal 500 ..4-500-1 .
IBM Color Display Replacement
505 4-500-2
IBM Color Display Vertical Hold
Adjustment 510 4-500-3
IBM Color Display Vertical Size
Adjustment 515 4-500-4
Diskette Drive 4-600-1
Diskette-Drive Adapter Removal
600 4-600-1
Diskette-Drive Adapter
Replacement 605 4-600-2
Diskette Drive Removal 610 4-600-3
Diskette Drive Replacement 615 .. 4-600-6
Diskette-Drive Mounting Bracket
Removal 620 4-600-8
Diskette-Drive Mounting Bracket
Replacement 625 4-600-9