Atari CX - Page 75

Keyboard Troubleshooting (cont.) .
1s there Ov on Pin 6
No
Is there t5 on Pins l,2,
of
U9 & Ull? 4 & 5 of U27?
1
b
I
1 Yes
Is the problem Yes
repaired?
i
I
Check capacitors &
resistors on Pins 1-8 I
I
of Port 1 for proper
value
& operation. I
1 Replace if defective. I
Defective US or open .
traces from US to U27.
Vac
If you are servicing a unit containing
PCB CA020 108, chip designators have
been chansed from U to A.
CX5200 Field Service Manual