On Sun, 12 Nov 2017 15:06:33 -0500, Paul wrote:

The cable has a red mark indicating pin 1.

The drive casing has a triangle marking pin 1 stamped in the metal.
You need a strong work light, and your wits about you, not to miss
these "hints printed in metal". It was the same thing when I
got my first optical drive to install, I entirely missed the
beautiful legend printed in the metal, which identified
everything.

Some drive cables have the alignment tab, but it's
quite common for installers to get it wrong, and

Both the cable and drive and mothervboard have an alignment tab. They
can only be plugged in one way. However, I could put the twisted end on
the MB side. But now I know it belongs on the drive end. Thanks.