Possible bricked Satellites after downgrading from v4.6.7.5 to v 4.6.3.16

So, I've tried the following after getting on the phone with support.  It worked for 1 of my satellites.  The other 2 still won't function.

1. Unplug everything from the router except your WAN port
2. Plug an eternet connection from the RBS850 (Satellite) to the RBR850 (Router)
3. Using a paperclip, hold the reset button in the back of the RBS850 until the light in the back turns yellow and flashes. The white LED in the front will also flash.  The reset process takes about 1 minute and 10 seconds to happen via the paperclip.
4. Wait while the satellite reboots and syncs with the router.  In my 1 successful case, I waited 5 minutes as the device did the white pulsating light.  Eventually it shows up in my device list in the Web based UI under "Attached Devices" -> "Connected Satellites"

Unfortunately my other 2 just don't get past the flashing light. I do notice that the light sequence is subtly different.  For a couple of minutes during power on, it's a pulsating on and off, where the light is clearly dimming and getting brighter.  After about 2 minutes, it switches to a continuous on, then off in 1 second intervals. 

Any thoughts?  I've also tried the connections described above, pressed the sync on the Satellite, then the Sync on the Router.  This hasn't worked either. 

I've considered uploading the firmware via FTP as described here.  

https://kb.netgear.com/000059633/How-to-upload-firmware-to-a-NETGEAR-router-using-TFTP-client

However, 192.168.1.1 is the default IP for the router, NOT the satellites. I've tried 192.168.1.250 as described in other posts, but the device just doesn't appear to be listening on that IP address. 

Note that I'm also observing the power light alternates from green to red on the back of the units that are failing to boot successfully.