small light on T400

What is the small light besides the cd-rom and usb adapter on the right hand side of the T400? It never turns off even in the sleep mode.
My T400 seems to eat approxmiately 10% battery in sleep mode because of this. How to turns it off?

 

It's a tiny LED, that does not cause the laptop to use 10% battery while in sleep. The main source of power usage during sleep is the sticks of RAM. The LED's power draw is tiny, nearly inconsequential. You can eject the CD drive before putting it into sleep, and I think that should keep the light off (the light indicates that the UltraBay is connected and powered on).

 

I don't know what the light is, but it's not eating your battery. How long is your comp in sleep mode before it's used 10% charge?

You know that computers are still on when in sleep mode, right? They use less power, but they're still operating.

Welcome to the forums, by the way.

 

Someone asked this a while back, I think... hmm. I'll check.

Edit: Aha! Google FTW. Your light may be related to this, along the lines of what MidnightSun was saying.

 

I meant I lost 10% battery during one night.
I realize that it should be put into hibernate mode instead of sleep.

I know the small light won't cost much, just wonder it might related to
something unusual happening. But it is just a LED. Thanks, guys.

 

Along these lines...

I don't suppose there's some magic method of disabling this LED or getting it to turn off during sleep or hibernate is there? Other than dismounting the drive. It never bothered me much on my T61, but I just received my W500 last night and the ultrabay status indicator for some reason seems to be much brighter and more prominent (it's quite deeply inset on the older model). Translation: it's kind of annoying when left sleeping in a dark room - probably three times brighter than the subtle sleep indicator on the lid.

IMHO as a UI designer - it's a pretty bad design choice and it should be off by default during sleep. 99% of the time, the ultrabay status is irrelevant during sleep (except for the fringe condition of changing the device during sleep - even then, I would have it go through a flash/on-period cycle, and then switch off, to indicate a successful mount-dismount). The only indicators that matter for a system in sleep are the battery status and sleep mode LEDs.

Oh well. Nitpicking.

Edit: it goes off when you use the Windows dismount (safely remove hardware) feature, but leave the device in the bay. The only problem is that you have to eject and then remount to get it to work again, I think. Still, I don't use the optical much, so I might keep it like this...