Atari CX - Page 69

Gray Bars Troubleshooting
I
Manually set the
5200 to the Gray Bars
att tern. I
I
1 B
Is there a +5V p-p
signal on the side of
Yes
R23, R24, & R25.
Connected to U 1 ?
I
Defective R23,R24,
R25 or open between
R23,R24, or
R25 and
R.F. Module Pin 4.
Is there a +5V p-p
signal on the U1
output pin?
2 A
Swapout
Repair
2) U2
I
or
3) U3 Replace
No.
Reference the line
on the chart below
which has the resistor
that did not have the
proper signal.
b
I
No
If you are servicing a unit containing
Line # Resistor # Ul Output U1 Input Pullup # US Pin #
I
Yes
I
CX 5200 Field Service Manual
I
Open between U1 out-
put
and that resistor.
I
PCB CA020108, chip designators have
been changed from U to A.
-
Is there a +5V p-p
signal on
the U1
input pin?
yes
L
Defective U1 or no
+5V or ground
to
U1.
b