I have an old WD My Passport 2 TB USB 3 external hard disc. It has worked fine for 10 years, but for the past week, it doesn't even show up in Disk Management on Windows or Disk Utility on Mac, not even as an unformatted hard disc. The LED keeps blinking on and off in a regular pattern, not the irregular pattern indicative of data being accessed. I don't hear a clicking noise.
It does show up as a USB device in Device Manager, so my understanding is that the computer is able to talk to the controller in the disk, but the controller is not able to talk to the disk itself.
I know the cable is not the problem, because another disk works perfectly with it. I know the OS or the computer are not the problem because I tried two different computers, a Mac and a Windows. I applied all software updates, and rebooted, just to be sure. I tried connecting it to the laptop directly, and via a powered USB hub, which made no difference.
After this saga began, it did show up once on my Mac, but was able to read data at only 900 KB/s. After an hour, the speed increased to the usual 30-40 MB/s and it ran fine after that. But the next time I plugged it into the Mac, it didn't work.
WD support has been clueless, as expected. Their diagnostics app doesn't even detect the disk.
Is there anything I can check before I throw away the hard disk?
I don't have valuable data on it, so this question is not about data recovery.