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Service Information
4-5
Table 4-2
Troubleshooting procedure
Step
Item/component
Required condition
Comments
1
2
3
4
5
6
7
8
GND pad
+5V pad
U107, pin 6
U107, pin 5
U113, pin 7 and U104, pin 1
U113 and U104, pin 2
U113, pin 3 and U104, pin 9
U109-U113, pins 11-18
+5.3VDC
ID CLK pulses
ID DATA pulses
STROBE pulse
CLK pulses
DATA pulses
Low with output channel on;
high with output channel off.
All voltages referenced to digital ground
(GND pad).
Logic voltage.
During power-up only.
During power-up only.
End of update sequence.
During update sequence only.
During update sequence only.
Output channel driver outputs.