My ReadyNAS - No disks detected

My first thought is that you should have updated your firmware years ago, and on through just a couple months ago when V6.10.9 came out.  But even if you do find a quick solution to your drive issue, don't update right away until you're sure it's really fixed.  No need to add another variable now.

You need to find out if the problem is with the NAS or the drives.  You can do that few ways, and doing them all is best.  One thing is to try booting with just one drive in "Read-Only mode" via the start menu.  If one doesn't work, try just the other.  One bad drive can bring down the entire SATA subsystem, or the power could be too weak to spin up two drives simultaneously.  Make sure you do this read-only, as if it's not, any write will make the two drives out of sync.

The next of those things is connecting each drive to a PC (via internal SATA, eSATA, or a USB dock) and testing them using vendor tools.  The PC won't be able to read the drive, but the tool will let you know if the drives are OK. 

The last is to install just a spare SATA drive (any size, just not containing anything you care about, because it'll be erased)  Then see if the NAS sees that drive and at least starts to initialize it.

If the drives pass testing and the NAS doesn't see a known-good drive either, then it could still be the power supply.  They can be found pretty cheap (12V5A with a standard 5.5 x 2.1mm barrel connector).  There is nothing internal to the NAS that is repairable by even an above-average user, and Netgear never offered repair services.  So if the drives are good and the NAS is bad, then you're either going to need a replacement ReadyNAS or PC based RAID recovery software to use with at least one drive connected to the PC.