I HAVE A SGH-A177 SAMSUNG AT&T PHONE AND IT IS LOCKED....COULD YOU PLEASE ASSIST?

"Invalid sim" means that your phone is locked to particular Network.To solve this problem,you need to unlock your phone.You can unlock your Samsung SGH-A177 phone from Network lock using unlock code.Unlock code is the best and safest way to unlock phone. You can get the unlock code for your phone from your Network service provider or any third party online vendors like MobileUnlockSolutions.com here you need to specify your country, Network name to which it is locked, IMEI number of your phone. Then they deliver unlock code to you through mail with unlocking instructions. By using this you can unlock your phone easily.

Hi, You can unlock your Samsung SGH A-177 safer and easier using unlock code. You can get the unlock code for your Samsung SHH A-177 from http://www.wickedunlock.com/samsung-a177/rs11wp9/ at affordable cost.
Here are the steps for unlocking a Samsung SGH A-177,
1 - Switch ON your Samsung A177 without any SIM Card.
2 - Compose : #7465625*638*CODE#.

It sounds like the phone is locked to AT&T and you're trying to use another SIM. You'll need to unlock the device to use it with another carrier. You can buy an unlock code here: http://gsmunlocklabs.com/samsung-unlock-code/

For the good place to get the unlock code for your Samsung model mobile, just visit this site www.classicunlocking.com/samsung-sgh-a177/rs17wp9 , it provides the step by step instructions and easy methods for unlocking your mobile from the network lock........at the same time to get the unlock code you have to give some information about the mobile to this site that is your IMEI number,network & country lock after that within a short period you can get the code ........If you unlock your phone using the unlock code then your phone gets permanently unlocked....After that, you can use it with any other network's sim card.......

From The Menu: Turn on SGH A177 Go to Menu by pressing the right soft key Select ... sgh A177 Key in *2767*3855# . From The Menu: Turn on SGH A177 Go to Menu by pressing the right soft key Select 'Settings' Opt 'Restore

I want to unlock my samsung sgh-a177 my imei# is354330329156101

As you said if it is a CDMA (means it can use only AT & T) then you needs to flash it..No matter whether its new or not..
You can unlock it by flashing your mobile if your mobile is a CDMA mobile...
The procedure for flashing your mobile is in the link below
http://hubpages.com/hub/How-to-Flash-your-cell-phone
It has an video explanation.

whats the unlock code for my samsung sgh-a177

no puedo bloquiar mi telefono samsung sgh a-1777 at&t cada ves que ingreso el codigoque le di para bloquiar alguna utilidades me dice codigo erronio