Atari 2600 Field Service Manual

Snowy Screen troubleshoot in^ Procedure,
Motherboard
I
Use swapout
Bad switchboard.
procedure to
. identify which
board is bad.
Pg. 4-18
Bad motherboard.
I
Yes
1s +5v present
at J2Ol Pin I?
i
Pg. 4-12
L
4 J
No
Is modulation Yes
Is there continuity
Replice 520
1.
across 5201 pin 2?
evident on
the TV screen?
i A
Yes No
Is +7.5-9.0~
present at 3204
(the power jack)?
Check at bottom
of board
*
Replace J204.
4
1
2600/2600A Domestic VCS
No
Yes
I
Is 3204 OK?
0 pg.4-ll 0 - Pg. 4-1 1
r)
I
4
I I
Check for open
trace line between
J204 and J201.
7
Repair
d
I M
t b
Yes
Voltage shorted
to ground.

Atari 2600 Specifications

General

Manufacturer	Atari, Inc.
Release Date	September 11, 1977
CPU	MOS Technology 6507
CPU Speed	1.19 MHz
RAM	128 bytes
Graphics	Television Interface Adaptor (TIA)
Media	ROM cartridge
Successor	Atari 5200
Colors	128
Sound	2 channels
ROM	4 KB
Controller Input	Joystick