I have a Sony VAIO VPCCW27FX laptop.
The History
It works fine (Windows 7 x64; no driver issues of any kind; has latest BIOS), except with a slight glitch:
Sometimes, it won't shut down/hibernate/standby properly. Instead, it goes into a "coma":
- The "power" and the "wireless" LEDs are on, but all the other LEDs are off
- There is no HDD activity whatsoever
- The display is completely off
- The fan is on
- The keyboard doesn't do anything: Ctrl-Alt-Delete doesn't do anything. Furthermore, I've even installed a driver to intercept Alt-SysRq-B and reboot the machine, but that doesn't work either
- The power button doesn't do anything (normally, it shuts down the machine)
The only option I have when this happens is to hold the power button to force the machine to turn off, and then turn it on again. (When it is turned off forcefully like this, it takes a little longer for the BIOS to initialize, presumably because of additional tests it runs.)
This has happened whether or not the computer is plugged in, so it doesn't seem to be battery-related.
The Problem
Since last night, my laptop has suddenly gone into this "coma" three times, and each time, I wasn't there to observe it when this happened. (I only came back to see it not working.) It used to happen very rarely, but it surprised me when this happened so often.
Furthermore, it didn't seem like a hibernate/shut down/standyby problem anymore: Today morning, it happened in a timespan of less than 10 minutes while plugged in (I wasn't there to see it...), which is weird because the Standby and Hibernate timeouts are set to a few hours, and the "Turn off display" and "Dim display" settings are both is set to greater than 10 minutes. (Edit: Actually, I might've messed that up -- the "Dim Display" setting could have been less. But I can't reproduce the problem. :)
So I'm a little stumped... I haven't seen it happen on other versions of Windows (e.g. XP) or on Ubuntu, but I haven't used them often enough to notice this, anyway.
Any ideas what might be causing this?