Power supply problems - 2 plates defective

Meanwhile, I have received this plate twice and now have both sent back because they did not run both to my satisfaction. The first panel was working at the beginning of wonderful until she no longer was recognized or not more delivery points. The problem showed up more often, so I was forced to reclaim it. At this point, kudos to Amazon, the totally uncomplicated a New sent me. Problem on this disk is almost certainly the power supply, that seems to be too weak (see also descriptions of anderern users). (Even the Trekstor support spoke of a power supply problem). In replacement, the power supply was not at all. My happiness about this whole thing was that I already had at no time data on the disks and the Exchange on Amazon was so smoothly. I am now for the Western Digital 320 GB external hard drive USB 2.0 decided that works smoothly so far.