Atari 400 Service Manual

• Fails Port test
• Fails RAM Test
• Fails Tone Test
Motherboard
RAM Memory Board
Motherboard
2
2
2
PICTURE QUALITY TEST
• Herringbone screen
• Snowy picture or no
picture
• Blurred picture
• White Dot Pattern on
screen (usually vertical
pattern)
• Picture upside-down when
running programmed
software. (Program
Cartridge)
Power Supply
RF Cable
Power Supply
RAM Memory Board
CPU Board
3
3
3
3
3
• Power LED not ON and no
picture
Power Supply 2
• Screen oscillation wgen
using Paddle Controller
Motherboard needs
Engineer fix
2
• Will not perform math
calculations
CPU Board 2
5.4.1 Troubleshooting -- Procadure Number One
This troubleshooting procedure is intended to be followed when the
Console System fails to power-up correctly. Symptoms include Green
Screen, Black Screen, Random Characters on Screen, or Unit Lock-Up.
This procedure assumes that the System Power ON LED is lit and the
screen exhibits some symptom of Console control. If these two condi-
tions do not exist proceed to Troubleshooting - Procedure Number Two.
ATARI Personal Computer 5-19

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)