New SSD, SATA w/ intermittent functioning, but mostly get "?" folder.

Macbook Pro 13" 2012-ish, hard drive failed, so put in a new SSD, loaded OSX onto it and it all worked briefly, but after a few days I suddenly got the "?" folder and nothing would fix it.

So, I then installed a new SATA cable from iFixIt, but now the drive isn't even seen when I boot into recovery and look for it using Disk Utility. For fun, I put the old SATA cable back in and every booted perfectly, but after a few minutes of working the computer froze. Upon rebooting I was back to the "?" folder. Tried the new SATA cable again and...nothing.

I saw a Youtube video of a guy who used electrical tape to cover the old SATA cable and keep it from shorting. I tried that also. Nada.

I'm about out of ideas. Any thoughts would be greatly appreciated

Thanks in advance!