PowerEdge R710 iDRAC 6 stuck, can't connect

The iDRAC can't be accessed, it tries to connect indefinitely, totally unresponsive.

Sometimes the web login page comes up, VERY slowly, but the login is so slow that I can't access.

I already read this article:

https://www.dell.com/support/kbdoc/en-us/000126703/how-to-reset-the-internal-dell-remote-access-controller-idrac-on-a-poweredge-server

and managed to reboot the iDRAC with the RACADM method (ssh access is very slow too and very often doesn't work):

racadm racreset soft

Anyway after the reboot, the problem didn't solve.

1- what should I do to resolve this issue?

2- I have a near dead hard disk to replace, can I identify it and put it offline via ssh commands?