Hello Hahn. So there's no other way to turn Secure Boot back on? No other way to get to the UEFI menu? Is it normal for it to take multiple tries of holding down the volume up button and pressing power on to get the UEFI menu to appear? I mean, it's not really a timing issue when it's just those two buttons and one's held down and the other's just pressed once, right? How long does it take the UEFI menu to appear after the Surface logo and red bar/unlock icon show up? Should I keep pressing the volume up button? For how long?
Is there a way to boot the device on a bootable USB key and do some diagnostics? As I mentioned, this is not my device., so I don't know if the owners have a Microsoft account or know how to get into it. I'll have to ask. Does the Surface have a TPM device on the motherboard, and could it be defective?
Thanks,
Cindy