Atari 800XL Field Service Manual

SECTION
J
SYMPTOM
CHECKLIST
The
Sympiom
Chrcklisi
ts d<^5ig^rd to
aid xhr
t#^hnirian
lo
arriving
at, lisied in iKe order
of
f^ilixe^
rapid dia|;no«is
ol problcmi. Each
symptom
is
accompanied by lomc po^^ihle cauies,
and SJiRgesled
remt^diei- Inatnictiona lor <rKna5irTr.b1
y/a^^^mbly,
are in
SECTION
of thi»
rn,tf«
SYMPTOM
POSSIBLE CAUSES
REMEDY
Sno*y
Screen
TV
Switch Box,
ON/OFF
switch,
Channel
Select
switch, RF Modulator
Adjust or rcptaccn
Defenivc Power
Supply,
Damaged
RF C-able
Replace
Defrctive
(open)
components
on JC
line-
Isolate
and replace
Defective (st*orted)
coTipor>ents IvDlaic and replace
on
*5A, B and/or
C
lini
Defective (shorted) LSfs
and/or ICs
Isolate
and
repair
Black/Crcy Screen YI,Q8,
9,
C109 TrDiiblc5hoot the clock
circuit and replace
defective component.
ftrd/B
rown
U2, 7-ZO,
21,
23,
26-30
U2-5,
U, 19,
28,
30
Isolate and replace
defective IC
Isolate
and replace
defective IC
BlL>e screen
Yellov screen
U2
U28
Replace
Replace
No Color or
Bad Color
RF Modulator or R3S Adjust or
replace
U17,
U20,
Ql,
Q3p
CR2, CR3 Troubleshoot color/video
circuitry-
Replace
de-
fective
IC/component,
Yl
Verify 3-579M5
MHz freq-
of
YL Replace if defective
SOOXL,
Computer
Field
Service
Maniial
3-1

Atari 800XL Specifications

General

Manufacturer	Atari
Type	Home computer
Release year	1983
CPU	MOS Technology 6502C
RAM	64 KB
ROM	24 KB
Operating System	Atari OS
CPU Speed	1.79 MHz (NTSC) / 1.77 MHz (PAL)
Graphics	ANTIC and GTIA chips
Display resolution	160×192 to 320×192 pixels
Sound	POKEY chip
Storage	Cassette tape, floppy disk
Ports	Serial, parallel, monitor, joystick ports