Mobile Repairing (Network Problem)

If there is no network then
1. Check antenna
2. Clean antenna contacts
3. Check for loose contacts of antenna
4. Then "manual search" network


if network searches the providers list then
1. Antenna is ok
2. PFO is ok
3. RF IC is ok

if there is no provider list displays then
1. PFO
2. Antenna Switch
3. FEM IC check or change