Dashboard, network and mycloud unreachable

I am using the MyCloud EX4 ultra.
After connecting an external USB drive to the NAS, I created a USB backup like I have done multiple times before. I started the backup and straight away the chrome browser I was using froze.
I briefly later on, had access to my network where I could see that the backup had seemed to work or be working. The new backup folder was there with around 8gb of data in it.
I kept on trying to access the dashboard and network without any more luck. The next day no access at all. The NAS stays connected to the USB drive, making lots of noise, busily doing something. At least the fan is working very hard. This makes 3 days now.
Normally a backup like this is finished in a couple of hours.

I have tried a 4 seconds reset which changed nothing.
I can’t try the 40 seconds reset because you need to do this from powered off. I can’t access the dashboard to turn it off or disconnect the USB !
If I just yank our the power cord can this damage the NAS and USB ?
What can I do when everything is frozne like this. Sounds like I should just be able to reboot the NAS, but if I can’t access the dashboard this is out.

thanks in advance

Hi uk-rich,

Slow dashboard or hanging problem can refers to low ram availability or heavy load on CPU. You can refer to the link below in order to resolve your issue.