Boot Error on BOOTCAMP Windows 8.1 “No bootable device, insert boot disk and press enter”. No keyboard shortcuts possible.

Thanks Loner T, for responding.

1. My iMac was purchased in January 2015. Factory upgraded: 1TB to 3TB, 8GB to 32GB ram, MacOS High Sierra.

See full spec in attached image:

2 . Yes I used to boot in and out freely, until now, I can’t. This because it hangs at the prompt “No bootable device..”.

However, earlier on I was able to screen snap your requested output. Find below image:

No Lightning-to-USB cable. Here’s mine (see image). It’s hard wired.

Is it an excluded (or bad) product, by any chance?

Hi Loner,

I am already on the Mojave. Just highlighted the OS the iMac first came in.

”Why are you running fsck_hfs on an APFS file system? You should be using fsck_apfs.”, I didn’t know that.

However, my problem right now really is that, I have pointed to the bootcamp windows installation as start up device. But maybe because I had earlier (in the windows 8.1) selected the “Advanced Startup” option to restart with usb/cd/dvd device (from the Boot Options Menu), the system no longer sees the windows installation OR it requires to complete the reset/refresh/restore cycle via its bootable intaller, before it can resume booting again.

Normally, I would just use the startup shortcut keys (f2, f8, f12, alt/option, etc), but none of that works since the Mac boot sector failed (Power Outage).

So I don’t know what to do. I am thinking of 2 options:

1. use a windows 8.1 bootable CD/usb to see if it will recognize it. Then I can go on to just restart the OS or refresh the installation.
2. try accessing the “Macintosh HD” from another Mac using a Thunderbolt cable even though I have not specifically put it in “Target Disk Mode”. Maybe I can then work something out via terminal?!

I already did that (when I could boot into MacOS Recovery). I selected the usb with Mojave 10.14.6 installation as “Startup Disk” from MacOS Recovery, and it started booting. When it got to the stage where it should now show sign-in, it instead showed a white general prohibition sign (the popular “ghost buster” sign). I thought, maybe if I did the same with a High Sierra it might work, since that is what the MacOS Recovery disk created by the same iMac is requesting for reinstall.

I also think it may be refusing a thumb drive.

However, with the current error prompt “No bootable device, insert boot disk and press enter”, I don’t even know if it will see the usb to boot from it, as it currently bypasses rEFInd and Linux boot devices on usb, to get to that point still.

Remember that no startup shortcut key is currently responding.

Loner T wrote:

Using a Mojave Installer USB (created by createinstallmedia - see How to create a bootable installer for macOS - Apple Support for reference) is not the same as a 'full' macOS Installation. Do you have Mojave installed on an external disk?

Also, have you run a SMC and NVRAM Reset?

I don’t have another Mac yet to run the “createinstallmedia” command on. But I’ll try that when I get one.

I have, however, turned my attention to the keyboard. My problem will be a lot easier to solve if I can use the startup shortcuts.

The shortcuts firmware resides in the logic board (if I’m not wrong), so why can’t the system see it on startup?

I use an Apple Magic Keyboard with Numeric Keypad, mine has a fixed usb-a connector cord.

I wonder if it will help if I connect via a usb-to-thunderbolt adapter to the thunderbolt port?