Atari 2600 Field Service Manual page 85

Pink a Getn
Not U d
C
r
een
Not
Used
Cunc
R e t
Switch
G e m
Not U A
Figure
4-8. Diagnostic Va t r ix Screen
with Defective P a t t e r n
Came
kka
Switch
Any missing grid lines or disrupted rectangles indicate an I/O line failure (see page 4-26).
Any missing
or
disrupted blue o r black reference lines indicate t h a t t h e r e has probably
been a microprocessor failure (see page 4-23).
Game
R e x t
Switch
2600/2600A Domestic VCS