I ordered a 2.5" IDE extension cable (male & female connectors) from Atlantic ComputerTech, 95 Horton Ave. Lynbrook, NY 11563 that has a defective female connector.
I didn't know it when I received it because I used a "needle probe" with a DMM to check the connections between the female connector and male connector. I discovered this cable was "out of phase" (top row of female connections are connected to the bottom row of male, and vise versa).
Then I found out there is a "true extension" after I called the company. I ordered the "true extension" IDE cable. When I received it, I verified that the connectors (male and female) are "in phase" using the same needle probe on my DMM.
When I connected a 2.5" IDE HDD to this extension, the computer did not "see" the HDD!!!!!!
I removed the HDD and decided to check every pin connector on the extension.
FEMALE CONNECTOR DEFECT:
It was when I used a 10X magnifier and a bright light that I noticed that there are no "sleeve" (don't know if right term) contacts in every "hole". The only contacts were at the end of each hole!!!!!!!! The tips of every male contact would have to press against the back of every hole in the female connector in order to make a good connection. Note: My needle probe simply touched the back of the hole contact.
The first cable I ordered, which I did not return yet, had exactly the same issue. I am going to call Atlantic ComputerTech about returning the cables for a refund (PayPal).
I don't expect to have a problem returning the cable for a refund, but if I do, I will let you know.