LG CE500 Service Manual page 72

Checking FEM & Mobile Switch
1
FL701
3
Check these circuit with High Frequency
Probe at each point.
You can see RF signal at Spectrum
Analyzer.
3) Check RF frequency at each point(1,2,3,4,5).
Can you observe good RF signal at proper
frequency?
• GSM850 190Ch. : 881.6MHz
• GSM1800 700Ch. : 1652.8MHz
• GSM1900 661Ch. : 1960MHz
2
4) Check RF Power at each point.
Can you observe good RF signal at proper
frequency?
At check point 1& 2
→ RF Power is almost same with input power set to
5) At other check point
→ GSM850 Insertion loss ~ 2.8dB
→ GSM1800 Insertion loss ~ 3.4dB
4 5
→ GSM1900 Insertion loss ~ 3.4dB
- 73 -
4. TROUBLE SHOOTING
equipment.
If not, change FL701(Mobile SW)
If not, change FL701(Ant. SW)