LG KF600w Service Manual page 71

Start
Check pin 7 (TP2)
Check if there is any major difference referring
To Figure 4.2.1(i) Is it similar?
YES
Check pin 5 (TP3)
whether it is higher than 3.4V.
YES
Check pin2(TP4) at U110(PA_R1 signal)
whether it is lower than 2.2V.
Replace U110
RF_IN fed up with CW signal
in low gain mode of PAM
Checking Flow
Checking Flow
at U110
at U110 ( Vcc)
YES
Waveform
Waveform
RF_IN
Figure 4.2.1(i)
PAM circuit is OK. See next page
YES
Check Vcc line
NO
Check PA_R1 line
NO
RF_OUT