LG KG70c Service Manual page 32

KG70C
3.2.4 Check RFT6122 Circuit 3.2.4 Check RFT6122 Circuit
Test Point Test Point
U106 Pin#12 U106 Pin#12
TX_ CP TX_ CP
Circuit Flow Circuit Flow
Check C174,C175 Check C174,C175
Check U106 Pin#12 Check U106 Pin#12
Check U106 Pin#23 Check U106 Pin#23
RFT6122 RFT6122
U106 U106
I,Q Level is Appear? I,Q Level is Appear?
YES YES
Level (near 1V) is Appear? Level (near 1V) is Appear?
YES YES
Output signal Output signal
(CELL) is Appear? (CELL) is Appear?
YES YES
Control Signal is OK Control Signal is OK
See next page to check See next page to check
PAM Circuit PAM Circuit
31
C174,C175 C174,C175
I/Q DATA I/Q DATA
U106 Pin#23 U106 Pin#23
CELL_OUT CELL_OUT
Figure 3-2-4 Figure 3-2-4
NO NO
Check U200 Check U200
NO NO
Replace U106 Replace U106
NO NO
Replace U106 Replace U106