LG MX8550 Service Manual page 68

MX8550
Check if there is any major difference referring
To Figure 4.2.1.4 (a). Is it similar?
Check if there is any major difference referring
To Figure 4.2.1.4 (b). Is it similar?
Check pin1 at U111(TX_ON signal)
Check pin15 at U111 (TCXO signal)
referring to Figure 4.2.1.4 (b). Is it similar?
Check pin2, 3, 4 at U111 referring
To Figure 4.2.1.4 (d). Is it similar?
LG Electronics Inc.
Checking Flow
Checking Flow
Start
Check pin23 at U111
YES
Check I/Q data at U111
YES
whether it is higher than 2.5V.
YES
YES
YES
Replace U111
RFT6150 circuit is OK. See next page
YES
Check U204 MSM6500
NO
Check TX_ON signal & MSM
NO
Check TCXO circuit.
NO
Check SBI signal line & MSM
NO
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