automatic standby stopped working

[Gary L. Drescher]

My PC no longer enters standby mode (S3) automatically, even when the
standby idle time is set to just a few minutes. It used to work several
days ago. I haven't installed any new drivers in the interim. The monitor
does turn off automatically after the interval specified for that. The
standby button still works manually; and once the computer enters standby
mode, it stays there indefinitely, until I wake it (it wakes properly). I'm
running XP Pro, all updates installed.

Is there any quick way to diagnose what's keeping automatic standby from
working?

 

[noone]

some background services, such as diskeeper when set to do background
defraging, will prevent the machine from ever going into standby. so will
background-like processes, like seti@home. did you enable anything like
that recently? how about an automatic virus-scan schedule?

 

[Gary L. Drescher]

some background services, such as diskeeper when set to do background
defraging, will prevent the machine from ever going into standby. so will
background-like processes, like seti@home. did you enable anything like
that recently? how about an automatic virus-scan schedule?

Nope. But I just succeeded in isolating the problem (by selectively
disabling startup items via msconfig). It turns out that automatic standby
is suppressed by lxbkbmgr (software for my Lexmark X1150 printer/scanner,
v2.0.2.2). I have no idea why this problem arose recently (the printer has
been there from the beginning, and its software has not been changed
recently). And I haven't yet experimented to see what functionality I lose
if I disable lxbkbmgr. But at least I know now what's causing the problem.