Samsung Galaxy Ace II

[#1]

Phone is locked to 02 and I thought if would not need unlocking.  Have activated giffgaff SIM but phone continues to instruct me to insert SIM.  Does this mean I have to unlock?

[#2]

Try factory reset make sure you backup every thing first...

[#3]

Once done it then ul have input giffgaff apn network settings in your handset manually roam correct to....

[#4]

Hi,
giffgaff will work fine with an O2 locked phone.
Check the sim contacts are clean, it's the right size for the phone, and correctly inserted.

[#5]

Thank you! I've done that and now its insisting that I don't have a SIM card installed. I've tried removing it, cleaning it, putting it back in and starting again but still get same message. Could the SIM be faulty?