I have had issues with older snap server models doing the same thing. And I am going to assume that these are not Windows Based models. I ended up sending them emails and they gave me the codes and instructions on how to check and fix bad sectors. Make sure that you have good backups bc if it does not work or if it does your data my end up corrupted. Also these models tend to go out after about 4 years in my experience so check the age and maybe look for something new.