W10 broke my working High sierra install

[NativeX]

Hmmm I do have a couple half-faulty HDDs laying about, I’ll give it a shot tonight. What difference does it make going external SATA?

 

[remington]

Have you thought about trying it with an external drive connected USB - something like the WD Passport drives? Or just a bare SSD with a USB-SSD adapter - something like this for example:
https://www.amazon.com/dp/B00XLAZODE/?tag=tonymacx86com-20

I use this and it works like SSD.

Corsair Flash Voyager GTX 128GB... https://www.amazon.com/dp/B079NVJPKV/?tag=tonymacx86com-20