I got blackberry 8310 from Spain I live in Pakistan when I Sim use the set instruction Sim invalid please solve my problem

SOURCE: RIM BlackBerry 7290 network problem

Unlocking is most probably the solution and 7290s can definitely be unlocked. You just eneter a software code but usually have to purcahse it. The locks are device (IMEI) specific.

SOURCE: RIM BlackBerry 7290 network problem

James

This seems to be the multimillion dollar question for Blackberrys and here is how this works.
There is no "magical"code for all BB's
Each Blackberry is item specific based on your IMEI which is located on the inside of your battery compartment.
Your best bet is to go to eBay or similiar and find your blackberry and look for the cheapest unlocking program. AT that point you will be able open your Blackberry.

SOURCE: will my blackberry 8310 sim card transfer to

SimCards are definitely meant to be transferred from one phone to another on GSM networks. You only need to ensure that the new blackberry you plan to get is "Global-Capable," meaning that it does have a physical slot for a SIM-Card, and if you plan on travelling Internationally, bue sure to contact your carrier prior to travel to have your phone provisioned correctly in the switch.

SOURCE: Blackberry Curve 8310 error message

Make sure that you are using the SIM card that came from your wireless carrier.

Try removing the battery from the back of it while it's ON. Leave the battery out for five minutes then put it back on.

If same problem occurs, contact your wireless carrier.

Have a great day!

SOURCE: blackberry 8310 no service

First, please download and install the latest version of BlackBerry Desktop Manager software from: https://www.blackberry.com/Downloads/contactFormPreload.do?code=A8BAA56554F96369AB93E4F3BB068C22&dl=DA5FB46338C8C0DCB1039F7898184FC5

Once installed, connect your BlackBerry to your computer via the USB sync cable. Open Desktop Manager, and click the Application Loader. On the right, you will see Update your device software. Click the Start Button, and if your BlackBerry is not on the latest Handheld Software, an update will appear. Select the update, and run the install. Be sure to select the option that backs up and restores your data. Once started, do not shut down your computer, or disconnect the USB sync cable as this could damage the device.

Once completed, your BlackBerry will restart and you will have the latest version available. This version has been known to correct various issues.

If the issue is still present, then it could be hardware related, and may need to be repaired or replaced. I would then suggest contacting your Provider for Hardware Support.