Why does it show insert sim card if its already insterted?

Do you want to insert other network sim or if your Blackberry Curve 8350I displaying insert sim card,if already sim card inserted.Don't worry i will help you.You can insert other network sim card in the phone by unlocking the phone from current network lock.To unlock Blackberry Curve 8350I use unlock code.Visit the site Wickedunlock.com get unlock code and unlock it easily.Then insert any GSM network sim card.If the phone displays insert sim card even though sim card is already in the phone.Please remove the sim card and replace it correctly.It is because the phone didn't detect the sim correctly.After inserting if it is display invalid sim or sim not valid message on the screen.It is locked to some network,you need to unlock it.To unlock use unlock code.Get code from online site and unlock it.

Clean the area of the SIM card detection pins and make sure that the card was inserted into the phone in the correct direction. If there is no detection with any card then the phone motherboard is defective but if the phone works with some card of a particular service provider then the phone is locked to that network-- in which case it will show and ask for unlocking code.

Check to make sure its not Backward...
2. Check the Sim card it self for damage the contact terminals should not be scratched or touching one another

You could try to remove your sim card.
Install battery and turn on phone without sim card.
Use phone without sim card and do some operations.
This will check if you phone is working correctly.
Turn phone off and install sim card.
Made sure sim card is install correctly.
If this does not work, it could be the sim card is bad.

if you sim card is already in there try putting it back in there may be you inserted in the wrong way.

there might be problem with the sim card holder. try to insert some piece of paper folded atop the sim card and close the sim holder

Sounds like phone is locked or firmware is bad

You have most likely already checked this, but just in case.....make sure the sim card is full inserted, and inserted in the correct position. (There should be a diagram showing which way to insert the card.

Hope this helps.
JD

now if you a civil person go on in cellphone shop and then acts the techician how your problem.....

call ur service provide...connect their internet and have a COLOUR LOGO....by this,when u will insert sim card...u will came to know that which sim is in the fone.