How do I get back off s7 cell to install sim card

Sim Network unlock Pin means you are trying to use it with any other network? It happens when you insert sim card from other network & the phone is locked by the provider. It can be easily unlock by getting the At&t Samsung Galaxy S7 edge sim network unlock pin from any reliable source like 24x7unlockcodes.com which provide At&t Samsung Galaxy S7 edge network unlocking

SAMSUNG Galaxy S7, S7 edge FRP/Google Lock Bypass - No ...
https://www.youtube.com/watch?v=k73dQOXPAJU

29 Mar 2019 ... Hey guys! This is my new video for SAMSUNG Galaxy S7, S7 edge FRP/Google Lock Bypass - No HushSMS, No Talkback, No add Call - New

If both Galaxy are for the same mobile carrier just move the Sim card from one cell phone to another.

Hi Chad if you're putting your sim card into a different cell phone make sure the samsung isn't locked to another service provider

look under the battery
also look here
Huawei Ideos Tablet S7 Inserting the SIM Card

Please don't do this yourself.

sim card signal

Not sure what Al is? But here's the info to unlock that make and model of phone, 2 ways to unlock the phone- Warning: Do not enter any wrong unlock unlock codes on your Samsung SGH-E350 mobile phones. If you enter over a certain amount of wrong unlock codes on your mobile phone, your phone may get hard locked and sometimes become unusable. Method 1: 1 - Switch ON your Samsung SGH-E350 with a NOT ACCEPTED SIM Card. 2 - Samsung SGH-E350 will ask for "Password". 3 - Enter the Unlock Code. OR (if the Samsung SGH-E350 shows "Insert Correct SIM Card") Method 2: 1 - Switch ON your Samsung SGH-E350 with a NOT ACCEPTED SIM Card. 2 - Don't bother about what's being displayed on your Samsung SGH-E350. 3 - Compose : #0111*CODE#. NOT ACCEPTED: We mean, to use a sim card from a network other than the network your Samsung SGH-E350 is locked to. CODE: Its the unique Unlock Code for your Samsung SGH-E350. If method 2 does not work, you can try method 2 again but this time without any SIM card on your Samsung SGH-E350. *** and this would be a valid unlock code- *2767*3855# IT RESETS THE MEMORY.MIGHT WORK WITH OTHER SAMSUNG MODELS.WILL NOT HARM YOUR PHONE. ~good luck~

According to Samsung's website, the device is only available on US Cellular/ Alltel. Making this device a CDMA only phone.
There is no sim card in this device.
http://www.samsung.com/us/mobile/cell-phones/SCH-U440ZWAUSC

You can Unlock the Phone from Network Lock using the Unlock code ,you can get the Unlock code from here Wickedunlock.com
and Follow the instructions below and Unlock it step by step:

Samsung SGH-A777 Unlocking InstructionsWarning : Do not enter any wrong unlock codes on your Samsung SGH-A777 mobile phones. If you enter over a certain amount of wrong unlock codes on your Samsung SGH-A777 mobile phone, your phone may get hard locked and sometimes become unusable.
Method 1:

1 - Switch ON your Samsung SGH-A777 with a NOT ACCEPTED SIM Card.
2 - Samsung SGH-A777 will ask for "Password".
3 - Enter the Unlock Code.

OR (if the Samsung SGH-A777 shows "Insert Correct SIM Card")

Method 2:

1 - Switch ON your Samsung SGH-A777 with a NOT ACCEPTED SIM Card.
2 - Don't bother about what's being displayed on your Samsung SGH-A777.
3 - Compose : #0111*CODE#.

NOT ACCEPTED: We mean, to use a sim card from a network other than the network your Samsung SGH-A777 is locked to.
CODE: Its the unique Unlock Code for your Samsung SGH-A777.

If method 2 does not work, you can try method 2 again but this time without any SIM card on your Samsung SGH-A777.