I have a complete confusion of boot problems on an old netbook. It's dual boot, details below, used every ~2 months for travelling.
1) One day it simply wouldn't boot. Power-light on, brief flicker of HD light, then blank screen, not even the slight glow of a black screen, it's like a monitor without power. Repeatedly pushing and holding the start button eventually produced a response and I could boot into Windows (suspected that an update maybe hadn't completed?). After that, restart from Windows or Mint gives me GRUB as nomral, but shut-down/start from Mint gives a dead startup screen again.
2) I decide even Mint needs to go, it is too slow anyway, and decide to test Puppy Linux. I make the bootable USB. Plug Puppy-USB into netbook, start, same dead response as before. Again repeat-push-hold start button to get to GRUB again. Test the USB on another dual-boot laptop, works beautifully.
3) Try the Puppy-USB in all the USB-ports, every one gives dead screen and messes up the startup.
4) I run out of ideas and hope look for exert advice on StackExchange. Does anyone have a suggestion about what's going on? Has something happened to the Mint shutdown? How to fix and how to get Puppy installed?
I have run "sudo grup-update", both with and without the Puppy-USB plugged in. Same output both times, basically same as GRUB menu.
Hardware: Samsung N150Plus, 1 GB RAM, 1 GHz, 32-bit, lots of HD space (200 GB+)
Operating System: Dual boot Mint-Cinnamon + Windows 7,normally selected in GRUB at startup, two partitions. Both OS are 100% updated.
Bootable USB: Xenialpup 7.5, using the 32-bit .iso found here http://distro.ibiblio.org/puppylinux/puppy-xenial/32/
UPDATE Reinstalled the whole system, both OSes, and it is now booting entirely normally.