Atari 2600 Field Service Manual

2600A Defective I/O Lines Troubleshooting Procedure
Determine
which
lines are
def cctive by
referring to
Figure b7.
Check the lines
indicated
as
defective for -5v
at
J202 or 1203
(See chart). I
Defective ,4202 Cap. Connecror
(RAM) Line No. No. Pin No.
15 C236 mn k
14 C229 3202-Pin 3
I
Is +5v present
Swapout
I I
Does Diagnostic
Yes
on the tinds)
L) A202 Matrix now look Yes
just chcckec'"
corrccr (see
Check the RAM
Repair open trace
(A2021 pin. Is +5v
beween A202 pin
pmmt theft?
shoned to +5v
and tht J20311203.
(Check trace lines).
I
b
I Arc them any-shorts?
I -
I
Check tract lids)
from defecrive pinh)
for hm to ground.
[5 ~5v now Yes
I present ar the
Repair
I
A202 pin?
I
I
Replace the
capacitor on
that line (see chart).
Docs the Diagnostic Swapout
Matrix screen now 1) A200
look correct (see Fig. 4-61
2) A201
2600/2600A Domestic VCS

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