HOW TO REPAIR INSERT SIM CARD PROBLEM
If after inserting the sim card, it shows the message ‘Insert sim card’ or 'insert uim card' or 'offline mode' then it is called sim card problem.
Solution :
(1) Check the Sim Card connector
(2) Clean the Sim Card connector contacts
(3) If it is Soldered Sim Connector then refresh it
with soldering iron
(4) Also check the sim card
(5) If there is Sim IC in the mobile dry solder
(6) Replace the sim IC
(7) Try Jumper Solution
(8) The problem is from Power IC or UEM IC.Dry solder/reball/change it