Atari CX 5200 Field Service Manual page 73

*** NOTE ***
f you are servicing a unit containing
PCB CA020108 ,
chip designators have
been changed from U to
Is pullup resistor
Repair
good?
l.ine II
LM0
LMI
LM2
CX 5200
Field Service Manual
Gray Bars
5200 to the Gray Bars
A.
Yes
Swapout
U5
1 )
2) U2
3) U3
/I
Resistor
R23
R24
R25
Troubleshooting
G
Manually set the
pattern.
Is there a + 5V p-p
signal on the side of
Yes
R23, R24, &: R25.
Connected to UI ?
Reference the line
on the chart below
which has the resistor
that did not have the
proper signal.
Is there a + 5V p-p
Yes
signal on the UI
output pin?
Is there a + 5V p-p
Yes
signal on the U I
input pin?
Is there a + 5V p-p Yes
signal on the U2 pin?
VI Input
UIOutput
2 3
6
7
11
12
4- 1 6
Defective R23,R24,
R25 or open between
R23,R24, or R25 and
R.F. Module Pin 4.
Open between UI out­
put and that resistor.
Defective UI or no
+ 5V or ground
to Ui.
Open between U2 pin &:
UI input.
Repair
or
Replace
U.5 Pin IJ
fI
Pull u p
RI8 31
RI9 22
23
R20