USB hard drive

[g_t_j]

As I already said, I have tried many power supplies with similar results. I even tried official raspberry pi 3 power supply (5V/2.5A). The best that I have found is a Samsung Tab's PSU rated at 5.1/2A. This seems to be the most stable of all.

I have also powered the board via the Euler bus but I haven't noticed significant voltage rise on the ports that feed the drive.

I'm now considering trying Lenovo's official charger for tablets which provides 5.2V in 2A.
https://nl.aliexpress.com/item/Original-...21206.html

Do you think this will help with my issue? Any suggestions?

many thanks

Does your pine64 board have a jumper on it for BATT and DC in (it's near where the wifi module goes)? Can you make sure it's in the DC in position, otherwise the PMIC may indeed current limiting the output to the USB ports. It would also explain why you're not seeing any voltage change when powering via microUSB and Euler. I suspect your drive is not getting the current it wants, as my external 1TB drive will draw in excess of 600ma when spinning up, and if the jumper is in the batt position, the PMIC is providing power to the USB ports, and current limits, which is what causes the clicks, as the hard drive isn't getting the current it needs to fully spin the hard drive platters up to speed. It it continues to be a nuisance, it may be easier to simply use a USB hub with external power pack, and you can use that to power both the pine64 board and the USB hard drive.

Thank you very much for the helpful post.

I was not aware of the jumper you mentioned. Checked it and it's on DC position. 
I'll have to try that power supply which provides 5.2V.

Any other thoughts are welcome.