Caps lock light blinks, hangs on boot

[audiodef]

Today I booted up my Lenovo Y520. Twice in a row, it got to a certain point - a different point each time - when the caps lock LED starting blinking and it hung there. I booted into Windows, then restarted from Windows to boot into Gentoo and it was fine.

What happened?

(I did a search for this condition for this laptop, only found one relevant hit, but it wasn't this exact model and there were no replies.)
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[Zucca]

Usually the blinking leds point to a kernel panic...
Try to disable TPM from uefi settings. It might cause Linux not to boot but would allow Windows.
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..: Zucca :..
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[audiodef]

I suspected Windows had something to do with it. I don't really know how TPM chips work - maybe booting up Windows cleared something up.
_________________
decibel Linux: https://decibellinux.org
Github: https://github.com/Gentoo-Music-and-Audio-Technology
Facebook: https://www.facebook.com/decibellinux
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