Security codes for phones

These are the default passwords or security codes for the phones I've been involved with.

Nokia 7210 - default password "12345" (e.g. when trying to delete all phonebook entries)

Song A768 (Chinese) - default password "1122" (e.g. when trying to delete all phonebook entries)

Samsung SGH D807 - "00000000" (This needs a PIN2 code when trying to delete both SIM and Phone address books. But if you try to delete the phone and SIM address books individually, you can use the above password)
The PIN2 code is provided by the SIM card so you may want to check with the provider.

GSM Coverage map

Here's the reference for world frequencies for GSM operators.

http://www.gsmworld.com/roaming/gsminfo/cou_in.shtml

The link is for India, but you can also see coverage for other countries.

Unlocking Samsung E105

credit to cellphoneforums.net

you would need the new network provider's SIM to unlock.

1. Change your phone's password back to 00000000 (8 number zero)
2. Power off your phone.
3. Take battery out --> take your T-Mobile SIM card out of the phone
4. Put ATT card in side the phone --> put battery back --> power phone on.
5. WRONG CARD message would appear on screen (in some case if the phone ask SIM unlock code , just put any number and it will show that message)
6. Enter *#9998*3323# and you see option exit ---> press right softkey to use function EXIT
7. After that one menu will show up, use arrow key go to number 6(or 7) Malloc Fail and use right softkey to choose this one.
8. Your phone will auto restart and now ATT network show on screen
* Until now your phone temporary unlocked ATT SIM CARD, to unlock your phone forever, please continue:
9. On screen, press *0141# and hit call button then screen appear "Persernalized"
10. Turn off phone --> take ATT SIM out --> put T-Mobile SIM in --> Power on
11. Screen ask " SIM unlock code"
12. Please enter 8 number zero : 00000000 ---> OK