I have a Samsung Impression SGH-A877. It's frozen - Black screen

Looks like the Flex cable which connects the motherboard to the screen has gone bad .. Please search for a autherised dealer .

To unlock your samsung mobiles with codes are the best one, because it is easy & safe also,
Follow the instructions :

Warning : Do not enter any wrong unlock codes on your Samsung SGH-A877 Impression mobile phones. If you enter over a certain amount of wrong unlock codes on your Samsung SGH-A877 Impression mobile phone, your phone may get hard locked and sometimes become unusable.
Method 1:

1 - Switch ON your Samsung SGH-A877 Impression with a NOT ACCEPTED SIM Card.
2 - Samsung SGH-A877 Impression will ask for "Password".
3 - Enter the Unlock Code.

OR (if the Samsung SGH-A877 Impression shows "Insert Correct SIM Card")

Method 2:

1 - Switch ON your Samsung SGH-A877 Impression with a NOT ACCEPTED SIM Card.
2 - Don't bother about what's being displayed on your Samsung SGH-A877 Impression.
3 - Compose : #0111*CODE#.

NOT ACCEPTED: We mean, to use a sim card from a network other than the network your Samsung SGH-A877 Impression is locked to.
CODE: Its the unique Unlock Code for your Samsung SGH-A877 Impression.

If method 2 does not work, you can try method 2 again but this time without any SIM card on your Samsung SGH-A877 Impression.

Get the unlock code from this site http://www.theunlockspot.com/samsung-sgh-a877-impression/rs10wp9/ to your samsung mobile........

Might be some connection problem on circuit board. You need to get the phone to repair service. Go to place where you bought the phone and take receipt with you.

Broken wires in flex cable between top and bottom of handset or a defective display.

probably there is problem with its flex,get it checked

I think you tried to reboot it and than restore it. If that does not work you may need a trip to the Apple store or call Apple tech support.
The second way:ADDIN TIMER software installation, set up at 2 am, 4:00, 6:00, 8:00 and 1:00 automatic reboot.

Further reading :The solution for Samsung impression screen turned black

I think that may be Wrong Code....You can get the Samsung Impression SGH A 877 model mobile Unlock code here http://www.superunlockcodes.com/samsung-sgh-a877-impression/rs12wp9/
at low cost and Free Unlocking instructions and UNLOCK IT.
Samsung SGH-A877 Impression Unlocking InstructionsWarning : Do not enter any wrong unlock codes on your Samsung SGH-A877 Impression mobile phones. If you enter over a certain amount of wrong unlock codes on your Samsung SGH-A877 Impression mobile phone, your phone may get hard locked and sometimes become unusable.
Method 1:

1 - Switch ON your Samsung SGH-A877 Impression with a NOT ACCEPTED SIM Card.
2 - Samsung SGH-A877 Impression will ask for "Password".
3 - Enter the Unlock Code.

OR (if the Samsung SGH-A877 Impression shows "Insert Correct SIM Card")

Method 2:

1 - Switch ON your Samsung SGH-A877 Impression with a NOT ACCEPTED SIM Card.
2 - Don't bother about what's being displayed on your Samsung SGH-A877 Impression.
3 - Compose : #0111*CODE#.

NOT ACCEPTED: We mean, to use a sim card from a network other than the network your Samsung SGH-A877 Impression is locked to.
CODE: Its the unique Unlock Code for your Samsung SGH-A877 Impression.

the touch screen on my AGH-A877 Impression has completely frozen up. I can only call or receive calls.

Drain the batteries completely then recharge it, if that doesnt work, get it replaced.

all you have to do is leave the better out for 15 to 13 seconds thats all