A couple of days ago I came back from a meeting to find my laptop had locked up. Power lights still on but the screen was blank (by which I mean black, though still "backlit" so not dead). Didn't respond to anything.
I rebooted and it powered up fine and I got to the login screen. I logged in and it seemed to be going fine for about 30 seconds (gmail notifier and pidgin popped up) then the same thing happened - black screen.
If I boot into Safe Mode it's all fine, no problems.
A virus is possible but seems very unlikely - it's a work laptop so is never used for anything dodgy and it's running a firewall and continually updated AV software. My gut feel is that this isn't malware and a Malwarebytes scan shows nothing.
I've tried removing everything from the startup folders (All users and my login), everything from the Run section of the registry (Local Machine and my login) and I've disabled every service which doesn't run in Safe Mode (assuming anything running in safe mode is OK) but the problem still exists.
I've scanned the memory for errors (all fine).
Any thoughts on what else I could try? Not necessarily looking for a solution, just suggested next steps.
EDIT: Resolution - so, no idea why at the moment but it turns out that the service causing the problem (or at least the one where if you disable it it the problem goes away) is the Power service. For now I can live without this so just disabling it until I have more time.