I found an old 2TB Hitachi External Hard Disk. It needs power from an external source to work. The 12V, 1.25A power input that came with it is not working. So, I connected another power input which is rated 7.5V, 0.35 A. It is getting connected to the pc(Logo lights up when I connect both power adapter and USB). But it is not being recognized by the PC as a Hard Disk. I can hear that the hard disk starts spinning and then it immediately stops. The logo blinks for few milliseconds and the same thing(hard disk trying to spin but failing) repeats. So, is that any issue with the Hard Disk or is it not working because of the power supply(maybe insufficient power)? It is not a windows issue, I have tried it on Linux as well. The same result on both of them. I have also tried using other USB ports (both 2.0 and 3.0). But the same thing is happening on either of them.
Sorry for my bad English.
Sorry for my bad English.