@mayur_ingle ok, glad to hear you're now seeing the expected behaviour with the working devices. The situation is a little unusual with the stuck devices. I didn't expect the bootloader to be impacted by the file system issue. I agree with what @crispyoz said above: If you are using an Omega2+ (through hole) my next step would be to insert it into a standard dock and view the boot process using minicom or some other terminal software. I looked at DockLight but haven't used it, but a raw terminal would remove any potential issues of handshaking or such causing the issue. For the stuck devices your next step should be trying them on a standard Dock from Onion, and using a simple terminal program like screen, minicom, or putty. Otherwise, these 3 devices might be write-offs. You can try to recover them by using an external device to rewrite the flash but we (Onion) don't recommend this procedure as a lot can go wrong.