Why did the SSD disappear from boot device priority?

Question

Boot disk

For some reason, the PC stopped booting from the SSD, it gives BOOTMGR is missing. The disk itself in UEFI EZ mode disappeared from Boot Priority, it displays only one HDD, DVD reader and CF reader. But the Boot Menu has all the installed drives, including the SSD with the system, and when the SSD is selected, the system boots successfully.

I tried to set the priority of devices for booting in Advanced mode UEFI, but for some reason there are all devices in the list of available options, except for the SSD.

Assembly on Asus Sabertooth P67 mother. Until recently, everything worked fine - a Win7 system on an Intel SSD and a file washer on two HDDs (1TB Hitachi and 2TB Toshiba). The problem surfaced after last weekend. Then Hitachi began to fall off. I got into the system unit, removed it for the sake of experiment and hooked it up to another SATA and SATA power. Everything worked. But then the SSD fell off. Inspection showed that the +12 wire on the power braid was cracked. In order, from the power supply unit on this spit, first a DVD hangs, then a Toshiba HDD, then an Intel SSD, and the last one was a Hitachi HDD. The wire has cracked near every SATA PWR connector from the Toshiba exit onwards. The PSU is modular, so I replaced the wire with a spare one. Each disk remained on its own SATA in the mother. Since that moment, the system itself has never booted normally from the SSD, only with manual selection in the Boot Menu UEFI.

Answer 1

I tried to set the priority of devices for booting in Advanced mode UEFI, but for some reason there are all devices in the list of available options, except for the SSD.

And in the boot options of Windows boot manager (or something like that) is there? If yes, then you need to choose it.