Sleep - no pulsing light with lid open.

Question

I have been aware of this little teaser for some time - possibly from when SL was installed. The MBP does not appear to be going to sleep with the settings on Energy Saver. The screen dims correctly and the light comes on at the correct time - but it does not pulse. The wake from this state is instantaneous when the trackpad or any key is touched/pressed. I recall that with Leopard I had to press the space bar which was followed by that funny noise as it woke up - HD kicking in?. The noise no longer occurs. I presume that the above is not normal? It is as though the MBP is not "properly" asleep, just resting, for want of better terminology.
If I shut the lid, sleep is also instantaneous and the light pulses. The same is true when sleep is selected from the menu.
I have also noticed that with the lid open and the light on that there is sometimes heat to the left of the trackpad - but not always.
I hate to say this but, having gone through a rapid battery failure (posted somewhere in that long thread under Power and Batteries), whether this had something to do with that rapid battery failure? In the past, I rarely shut the lid, just walked away. (A new battery has been fitted).
It can be taken that throughout all of the above that the power was plugged in.
Any ideas would be much appreciated.
Thanks
TY

Answer 1

Hi again TYDYsails,
These problem are almost always caused by third party hardware or software that polls the computer at regular intervals, interrupting the normal "timed" sleep process. They can sometimes be an absolute $%^& to resolve.
Common culprits can include:
Hardware attached to the USB or FW ports , or less usually, a router or other device attached to an ethernet port.
Software that regularly scans things. I have seen many different things implicated here at different times. Usually the problem eventually gets sorted out with an update of the software, so be aware of anything that you are using of this type that might not be the "latest".
Virus checkers, hardware monitors that regularly "poll" the HD or other components, "Button press" software associated with scanners or all in one printers, adds on like "Growl" that provide alerts of one kind or another, programs or widgets that provide regular "updates" using the net ( TV program guides are a good example) and so forth.
A good way of narrowing down the field a bit (once you have disconnected any hardware that might be involved - even USB hubs with nothing else connected have been known to cause the problem in the past) is to take a look at the log files.
Fire up "Console" from your utilities folder and choose the "System" log in the left hand pane. Type in "sleep" in the search field and look for entries that roughly correspond with the time when the computer was meant to be dozing off. Now repeat the process by type in "wake" instead.
You should find something that is either preventing sleep or causing an immediate "wake" after sleep has occurred.
Another useful check can be to take a look at Activity monitor before and after the "non-sleep". You may notice an unexpected process running in the background that is simply continuing to run through the period concerned, simply preventing the set "sleep" interval from ever being reached.
Another possible cause can be network related. If you have your computer acting as a file server for other computers , then the normal "timed" sleep from energy saver won't occur as long as they remain connected. (Using the "sleep" command from the menu, or closing the lid will let it sleep in these situations, but timed sleep will not occur).
Finally you need to think about other sorts of "network" related activity. Active Bluetooth devices nearby can sometimes be a cause.
THis wouldn't have caused battery failure as such, but it would have reduced battery charge life substantially if you were often using your computer on battery and relying on the computer to go to sleep on the basis of times set in Energy saver. It could also have increased the risks / frequency of "sudden shutdowns" and the like, if the battery was already "going bad", by more rapidly lowering the amount of power available to meet transient power demands.
Cheers
Rod