LSQVL(LS-QVLC62) Disk replacement

[plasticpig]

The unit had 4 drives (all same size and model number) in it set up as a single 4 drive raid. Disk 4 failed and I have bought and fitted a new drive with the same size and model number as the original. On turning back on the power light flashed for a fair while and the settled to repeating one long orange flash a two short orange flashes with all four disk lights green. The system-storage-disk display shows Array 1 with - as its status, Disk 1,2&3 as status Array 1 and disk 4 as status Removed. Below the disks it shows Array 1 Raid 5 status error. The only option available for disk 4 is Format Disk. This data viewed by logging in as admin to http://unit_ip_addr/static/root.html#

How please to add the new drive to the array and repair/fix the problem without losing the data on the array?

Apologies if the solution is already here somewher, but I couldn't find it. Any and all help gratefully received.
Thanks
:-[   :'(

[oxygen8]

http://np.faq.buffalo-global.com/app/answers/detail/a_id/13692/p/31,33,3748,3750

[plasticpig]

Thank you for that reference - it pointed me at http://np.faq.buffalo-global.com/app/answers/detail/a_id/14970 which I hadn't found before and solved the problem.

Am now waiting and hoping that the raid rebuild is successful.
Thanks