Atari 800 Field Service Manual

800
POWER-UP
CATASTROPHIC FAILURES AND BASIC OPERATIONS
BLACK/GREY SCREEN
Is
the screen black
or gray
YES
NO
Go
to
GREEN
/YEUXW
SCREEN.
Page
7-6
MOTE
I
See Table
7
-1
. start
at the top of
it and
trace
back until
clock
signal
appears,
indicating which
component
has failed.
Check Power
Supply-
Board for:
Is there
'Sv
on J201
Pin
1
YES
Is
there
•I2v
on
J201, Pin 21
YES
Check the CPU
Board for:
Clock Circuit
(see
NOTE
1)
Chip Reset Voltages:
Is there
^v
on
A302. Pin 36 and
A303. Pin 40
YES
Replace
CTIA/GTIA
{A301)
NO
Check,
repair,
or
replace
the
following;
Voltage
Regulator
CR204
and
CR205
Replace
1N4001
type
diodes
with
1N539I
(C017988)
Check
C203
-
C205.
and C212
NO Check, repair,
or
replace the following:
Voltage Regulator
(A201).
CR204
and
C203
-
C205
ML
Repair
Is
a
clear
MEMO
PApl
YES
on
the
screen
P"^
Go to
POWER-UP,
PART II, Paffe
7-8
NO
Go
to
C,
next
page
ATARI
Home
Computer
7-4

Atari 800 Specifications

General

Processor	MOS Technology 6502
Processor Speed	1.79 MHz
ROM	10 KB
Graphics	ANTIC and GTIA chips
Release Year	1979
Display Resolution	up to 320 x 192
Colors	128 colors
Sound	4 channels
Storage	Cartridge, cassette, floppy disk
Ports	Cartridge, serial, monitor
Operating System	Atari OS