Atari CX - Page 102

KEYBOARD TROUBLESHOOTING
Is the failure on
Port l?
Manually select
Pokey Adjust
Test, pg. 3A-2.
I Yes
Are there a 5V p-p
Pins 9 and 10 of A1 1,
A9, AlO?
d
Is there a 5v p-p
square wave on pin
12 of A5?
n J
I, Replace A27.
I
I
Are there 5v p-p
square
waves on Pin
6 of A9 & AlO?
r
No
I Repair Open trace.
I
L
I
Check for 5v p-p
Note: Some 5200 2-port boards have pins l,8,9,lO and 1 1
of A7 jumpered together on the solder side of the
PCB. Future PCB's will incorporate this jumper.
--.
Do not add these jumpers to the 5200 2-port board.
CX5200 Field Service Manual
4 A-22
Replace A7.
signals at pins
19,20,21,22 of A7.
1
I
i
No
,