I found the one that described removing the "backup battery" under the wristrest. Once I removed that, and replaced it... everything came back together, and the laptop booted (with generic factory settings).
Difficulty in getting to the battery aside, he just did a regular CMOS reset, the standard technique for getting otherwise unusable systems back to a good state.
Now that you posted this, I think I recall one friend telling me that hibernation killed his laptop. But this was over 10 years ago and I only know about one such incident.
OTOH, what UEFI gave us is basically a portable and convenient API to brick any machine from any OS.
Difficulty in getting to the battery aside, he just did a regular CMOS reset, the standard technique for getting otherwise unusable systems back to a good state.