Unable to install macOS/OS X

The hard drive cable in the MBPro 13" (mid-2012) non-Retina model is known to have an extremely high failure rate. This particular model is still supported by Apple so you could take it to an Apple Authorized Service Provider or Apple Store for service. There is a free repair program which I believe is still active for the replacement of the hard drive cable. An independent Apple Service Provider may be a better option as they may offer a third party SSD if the hard drive is found to be defective, plus they should replace the cable for you as well.

You could try running the Apple Diagnostic to see if it reports any issues.

You could get an external drive an install macOS on it. Connectors:

USB 2 - up to 5 Gbps

FireWire 1 - 800 MBit/s

Thunderbolt 1 - Thunderbolt 1 (up to 10 Gbps)

Any of these should give acceptable performance.

R

medamine101 in response to HWTech
Went to the Apple store, the problem was indeed with the cable. Unfortunately, the free cable replacement no longer appears to be a thing, but at least the problem part is known. Thank you so much!

Sorry, it is limited to three years from date of purchase (first sale). For some reason I thought this had a longer term.

The cable (and a replacement hard drive/SSD if needed) is extremely easy to install on a mid 2012 MBP. You can get it at OWC (macsales.com); or take it to an authorized service provider. Here is an install video:

https://eshop.macsales.com/installvideos/macbookpro_13_unibody_mid12_hard_drive_cable/

Could take it to an apple store.

Run hardware diagnostics.

https://support.apple.com/en-us/HT201257

Should be able to run Majove