I borked the Linux Mint 16 install, over a year ago, due to lack of awareness of uEFI and operator error. Windows 8 was completely wiped out and will not be replaced.

Normal boot fails and defaults to the prompt: MBR:__

I managed to get rEFInd installed, but I'm not sure where it is - maybe /dev/sda5.
I recall following instructions to edit some grub files with rEFInd entries, at the time.

I have to press F12 on every boot to see the boot options as presented by rEFInd. Currently installed are LM15 in BIOS/MBR mode and LM16 in uEFI/GPT mode. I want to continue with the uEFI/GPT mode because the BIOS/MBR mode is now aging fast.

I have an updated rEFInd application which is installed alone, on another USB. I seem to have installed on /dev/sda, but not sure where - maybe on /dev/sda2, which was the origianal boot. I reformatted /dev/sda1 but the process wiped out 'volume labels' and only /dev/sda3 and /dev/sda5 show up in the file manager.

How can I fix the boot sequence before installing LM 17 LTS.?

You can get detailed information on boot files, drives/partitions and uuids in addition to other relevant information by googling "bootinfoscript", going to their page, reading the instructions, downloading and running it.

Thank you, yancek. I can see, agian.