please help with 9520

[tuscan7869]

hi all first time at this,i need help with this phone,the mobile is factory unlocked not barred from original branded name,problem i have is only orange and 3 sim cards will work with low signal strentgh , i can manually connect to vodafone and o2 but it looses signal within 10 seconds, as i am currntly on o2 this is a massive problem for me all i get is sos in red,have tried my sim in another phone and thats works fine with good signal strentgh has anyone any ideas as wot to do with this as this is my first blackberry and would like to keep it for awhile.

i have just checked with voafone asking them to check the imei number and its not coming up as stolen or contract with no issues but the phone will only work with either a t-mobile,3 or orange sim card does this mean it was unlocked improperly

[blackberry-unlocking710]

It can't be unlocked improperly,
When unlocking a Blackberry device it's simple done by a unique unlock code, if the unlock code is accepted then it's unlocked.

Then the unlocked Blackberry Storm 9520 can work with sim cards from other carriers.
see if the bands that used by your carrier fit the 9520 frequency bands support for 2G - GSM 850 / 900 / 1800 / 1900