If your connection to the internet is working correctly using another system, then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.
=== Update (05/04/2017) ===
Clearly, your HD or the HD cable is having problems. At this point just restart your system as the process is frozen.
Hopefully your system is able to start up, if not you'll need to find a friend with a Mac so you can either connect your system to theirs in Target Disk Mode or so you can create a bootable OS installer USB drive.
* [https://support.apple.com/kb/PH25318?viewlocale=en_US&locale=en_US|macOS Sierra: Transfer files between two computers using target disk mode] In this case you'll run Disk Utility from your friends system to test your systems drive.
* [http://www.macworld.com/article/3092900/macs/how-to-create-a-bootable-macos-sierra-installer-drive.html|How to create a bootable macOS Sierra installer drive] Here we can first run Disk Utility from the USB drive to test the internal disk and/or do the OS install from it.
=== Update (05/05/2017) ===
-
It's not uncommon for the cable in this series to give out. You may in-fact notice the HD will work whereas the SSD won't! This is do the ability of the SSD to move more data across the cable so any minor defects in the cable show up under its load.
+
It's not uncommon for the cable in this series to give out. You may in-fact notice the HD will work whereas the SSD won't! This is do to the ability of the SSD to move more data across the cable faster so any minor defects in the cable show up under its load.
Here's the IFIXIT guide to replace the cable if its still having problems: [guide|10762|MacBook Pro 15" Unibody Mid 2012 Hard Drive/IR Sensor Cable Replacement} and here is the cable you'll need: [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Unibody-Mid-2012-Hard-Drive-Cable/IF161-100-4]
If your connection to the internet is working correctly using another system, then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.
=== Update (05/04/2017) ===
Clearly, your HD or the HD cable is having problems. At this point just restart your system as the process is frozen.
Hopefully your system is able to start up, if not you'll need to find a friend with a Mac so you can either connect your system to theirs in Target Disk Mode or so you can create a bootable OS installer USB drive.
* [https://support.apple.com/kb/PH25318?viewlocale=en_US&locale=en_US|macOS Sierra: Transfer files between two computers using target disk mode] In this case you'll run Disk Utility from your friends system to test your systems drive.
* [http://www.macworld.com/article/3092900/macs/how-to-create-a-bootable-macos-sierra-installer-drive.html|How to create a bootable macOS Sierra installer drive] Here we can first run Disk Utility from the USB drive to test the internal disk and/or do the OS install from it.
=== Update (05/05/2017) ===
-
It's not uncommon for the cable in this series to give out. You may intact notice the HD will work whereas the SSD won't! This is do the ability of the SSD to move more data across the cable so any minor defects in the cable show up under its load.
+
It's not uncommon for the cable in this series to give out. You may in-fact notice the HD will work whereas the SSD won't! This is do the ability of the SSD to move more data across the cable so any minor defects in the cable show up under its load.
-
Here's the IFIXIT guide to replace the cable if its still having problems: [https://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Mid+2012+Hard+Drive-IR+Sensor+Cable+Replacement/10762|MacBook Pro 15" Unibody Mid 2012 Hard Drive/IR Sensor Cable Replacement} and here is the cable you'll need: [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Unibody-Mid-2012-Hard-Drive-Cable/IF161-100-4|MacBook Pro 15" Unibody (Mid 2012) Hard Drive Cable Apple P/N 923-0084]
+
Here's the IFIXIT guide to replace the cable if its still having problems: [guide|10762|MacBook Pro 15" Unibody Mid 2012 Hard Drive/IR Sensor Cable Replacement} and here is the cable you'll need: [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Unibody-Mid-2012-Hard-Drive-Cable/IF161-100-4]
If your connection to the internet is working correctly using another system, then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.
=== Update (05/04/2017) ===
Clearly, your HD or the HD cable is having problems. At this point just restart your system as the process is frozen.
Hopefully your system is able to start up, if not you'll need to find a friend with a Mac so you can either connect your system to theirs in Target Disk Mode or so you can create a bootable OS installer USB drive.
+
* [https://support.apple.com/kb/PH25318?viewlocale=en_US&locale=en_US|macOS Sierra: Transfer files between two computers using target disk mode] In this case you'll run Disk Utility from your friends system to test your systems drive.
* [http://www.macworld.com/article/3092900/macs/how-to-create-a-bootable-macos-sierra-installer-drive.html|How to create a bootable macOS Sierra installer drive] Here we can first run Disk Utility from the USB drive to test the internal disk and/or do the OS install from it.
+
+
=== Update (05/05/2017) ===
+
+
It's not uncommon for the cable in this series to give out. You may intact notice the HD will work whereas the SSD won't! This is do the ability of the SSD to move more data across the cable so any minor defects in the cable show up under its load.
+
+
Here's the IFIXIT guide to replace the cable if its still having problems: [https://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Mid+2012+Hard+Drive-IR+Sensor+Cable+Replacement/10762|MacBook Pro 15" Unibody Mid 2012 Hard Drive/IR Sensor Cable Replacement} and here is the cable you'll need: [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Unibody-Mid-2012-Hard-Drive-Cable/IF161-100-4|MacBook Pro 15" Unibody (Mid 2012) Hard Drive Cable Apple P/N 923-0084]
If your connection to the internet is working correctly using another system, then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.
+
+
=== Update (05/04/2017) ===
+
+
Clearly, your HD or the HD cable is having problems. At this point just restart your system as the process is frozen.
+
+
Hopefully your system is able to start up, if not you'll need to find a friend with a Mac so you can either connect your system to theirs in Target Disk Mode or so you can create a bootable OS installer USB drive.
+
* [https://support.apple.com/kb/PH25318?viewlocale=en_US&locale=en_US|macOS Sierra: Transfer files between two computers using target disk mode] In this case you'll run Disk Utility from your friends system to test your systems drive.
+
* [http://www.macworld.com/article/3092900/macs/how-to-create-a-bootable-macos-sierra-installer-drive.html|How to create a bootable macOS Sierra installer drive] Here we can first run Disk Utility from the USB drive to test the internal disk and/or do the OS install from it.
If your connection to the internet is working correctly using another system., then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
+
If your connection to the internet is working correctly using another system, then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.
If your connection to the internet is working correctly using another system., then it sounds like the drives SATA cable is gone or you are not using the proper SSD drive for the system.
Can you tell us your exact model so we can guide you the rest of the way. Plug in your systems S/N here: [http://www.everymac.com/ultimate-mac-lookup/]. You'll find it in the 'About this Mac' or on the bottom cover. Paste the URL link here so we know what you have.