"My external hard drive has stopped working. It is a Samsung product. Powered via the USB cable. I have changed the cable and confirmed that is not the problem. It makes no sound or movement when connected to any computers. I need to extract or recover my data.".
I read that you've done some fault finding on your Samsung hard disk drive already! Good, this makes my job easier. Eliminating items like the cable is a sensible thing to do and I've seen, on more that one occasion, a cable being responsible for the fault. In your case, describing the fault as you do, to me it seem that your Samsung external hard drive is damaged. Googling something like 'damaged external hard drive recovery' pulls back many results and I had a look at some of them. The best sites I could find were http://computersciencelabs.com/ a site that has a corporate feel that is all about data recovery. It has some interesting information on it, including stuff on the forensic examination of computer disks and also obtaining the information from CCTV - much of which is written to hard drive these days. A less corporate site but one equally as good which is also awash with information pertaining to the extraction of data from Samsung (and other) hard drives is http://24hourcomputerrepairs.com. Many of the recent articles are about computer forensics involving hard drives and CCTV but take a look through the articles and you'll notice plenty of useful stuff.