NV+ won't boot - firmware error - USB recovery not working

What HAPPENED BEFORE:
ReadyNAS NV+ system would intermittently reset (once every 5 to 15 minutes). To try to correct the issue it was updated to RAIDiator-V4.1.10. System continued the reset issue after the update. All hard drives were replaced with new drives.

What is HAPPENING NOW:
After welcome, system says Booting, Please wait... (no drive LEDs are on) stays in this mode for about 90 sec.
Then the fan quiets down and the LCD screen says:
Booting... (for about 10 seconds), then on the second line it says:
ERR: Bad firmwar
then,
LED 1 and 2 blink, then all four LEDs blink, then the sequence repeats.

I downloaded the image file: ReadyNAS_USB_Flash_Recovery-4.1.10.img
I wrote it to three different USB sticks using NTRawrite in Windows CMD mode
All writes were successfully verified.
I inserted each USB stick into the NV+ front USB slot (rear slots are empty) and tried the following boot procedures.

Powered on NV+ while holding the Backup button. The LCD showed:
Boot Diag
Please wait...
then,
Booting... (fan slowed) for a few seconds, then back to:
ERR: Bad firmwar

When I hold the Backup button a while longer during power up, NV+ displays:
User Diag
Please wait... (for about 60 secs)
then, back to Booting..., ERR: Bad firmwar

When I just use the Power button and hold it for 20 secs for USB boot, the screen displays
Bios info
USB Init (I can see the USB key flashing indicating the NV+ is accessing it)
then,
Welcome, then,
Booting
Please wait... (for 90 secs)
then,
Booting...
ERR: Bad firmwar (alternating 1&2 and all four LEDs)

I'm totally lost as to how to proceed...

>>>>> PLEASE HELP ! <<<<<<< :(