I have discovered that incorrectly made Sata/e-Sata cables have been available on eBay. When I had problems getting a Sata harddrive to work with a e-Sata port on a controller card I assumed that the problem was with the card but it was actually a faulty cable which had been assembled incorrectly. This guide will show you a simple visual check to find out if the cable is assembled correctly which involves folding the cable back on itself without twisting so that the two connectors are next to each other like this.
Sata to Sata internal cable
The connection from a port on a Sata controller to a Sata drive is a straight pin 1 to pin 1 Sata male to Sata male connection. If the cable is folded back as above you should see something like this.
As this is a straight pin 1 to pin 1 cable the metal contacts are both on the same side of the connectors (this is the easy example as both connectors should be the same way around)
e-Sata to Sata external cable
To connect a Sata drive to the e-Sata port on the backplate of a controller card the cable is a crossover pin 1 to pin 7 Sata male to e-Sata male connection. If the cable is folded back as before you should see something like this.
As this is a crossover pin 1 to pin 7 cable the metal contacts should be on opposite sides of the connectors. e.g. in this picture they are on the right side of the Sata connector and the left side of the e-Sata connector.
I currently do not have an example of an e-Sata to e-Sata external cable but when I do I will add it to this guide.
The faulty cable that I purchased on eBay was incorrectly wired as a pin 1 to pin 1 straight Sata to e-Sata and thankfully is no longer sold by the seller. The working Sata to eSata cable pictured here was made by Pluscom and purchased from the ebay seller tm-direct from here but I am sure that there are other sellers with the same product.