ReadyNAS 104 - err: Used disks Check RAIDar

Hi all, 

I've had sporadic issues with disk 3 being degraded, then coming good again, then being degraded. Recently the ReadyNAS front pannel indicates the following: "err: Used disks Check RAIDar", I attempted to access the Admin page however when attempting via both the IP and the hostname the device is unavailable. The IP is static, and I can ping it successfully. I attemted to use Putty to access it and get the error "Network Error: Connection refused". 

a. How do I access my Admin page if the above doesn't work

b. I attempted to turn off the device by pressing the power button 4 times, nothing happens. Hard power off conducted - nil effect

c. Lights indicated: Disk 1,2,3,4 illuminated constantly, Act illuminated, Power flashing at a constant rate of 1sec

d. Firmware update occurred recently (latest version with no others available - I cannot recall the version number sorry). Device worked for about a week or two following the update. 

e. Device has no third party apps installed. 

f.  Device has been functioning correctly for approximately 2 years prior to this event.

Any suggestions appreciated