Nokia 920C - Page 18

5 Troubleshooting
5-4 720C/920C
5-1-4 S Correction Failure
S1~S5 signals are right at each
frequency block?
Check S1 ~ S5 signal.
Check and replace
C430, C431, C433, C434, C435,
C437 C441, C453, C454, C455, C456, C457,
Q409~Q413, Q451~Q455, Q456~Q460 .
Yes
5-1-5 H_Lin. Failure
IC201 Pin 21 voltage varies with
different H_Lin. DAC values?
IC403 Pin 7, 8 voltage varies with
different H_Lin. DAC values?
Check +12 V line.
Check some parts around IC403.
Check L403.
Yes
Yes
No
Check and replace IC201.
No
Replace IC201.
No
5-1-6 Invariable H_Size
IC261 Pin 28 voltage varies with
different H_Size DAC values?
IC401 Pin 6 output duty varies with
different H_Size DAC values?
Check some parts around IC261 Pin
28, IC401.
Yes
No
Check and replace IC261.
No