Snoopdogie187

Hi, I have a toshiba Satelite A215, and altec lansing spakers that I use with it. I have noticed for a while that the speakers make a hum sound with the laptop, the volume never mattered at all, even if muted. What I just realized is that it only does this when the laptop is plugged in, and never when running on battery. The hum also goes away if I conect a monitor to it (even if the mointor is off, as long as its plugged in). The mointor doesnt even have to be conected, just as long as the outside of the cable (the metal part where it conects to the port) is touching the port. I guess just attacking like a ground to the laptop.

Is this something I should worry about and what should I do about this? I'm probably going to call toshiba soon about it as I think the laptop is still under warrenty.

TriggerFinger

Hi,

I am not really sure but somehow I think this has something to do with grounding. Check the power plug of the laptop and of the external speakers. A grounded plug usually has a third (rounded) prong. The reason why it does not hum when an external monitor is attached is probably because the monitor has a ground in its plug.

Snoopdogie187

the monitor I know is the only one with the third prong. I'm not sure how I would change this though or fix this without having the monitor always conected.

TriggerFinger

Are you using a surge protector or like a UPS? Check if the surge protector has a third prong on its plug. Plug both laptop and speakers there. May be that could help.

Snoopdogie187

using an apc UPS. Everything for the computer is plugged into that, including the monitor. and it does hav a thrid prong.

TriggerFinger

So I assume the speakers plug in there too but I doubt if the speakers plug has 3 prongs. Btw, where is this UPS located (near the speakers)?

Snoopdogie187

yes the speakers are also plugged into it. and the speakers only have 2 prongs. It is located right next to the sub (whichalsohouses all power stuff) but the speakers never make a sound unless its conected to laptop like i said and it doesnt matter if ups and speakers are apart, thats how it was last week.

TriggerFinger

I understand. I did a quick search on the issue and it points to a grounding problem combined with a network of cables coming from one source. You can try to plug the speakers in a different outlet or supply.

I found a good information on the topic here:

http://forum.ecoustics.com/bbs/messa...79/180767.html

Snoopdogie187

Do you think it would be possible to ground the sub (the amp and everything really) by replacing the wire with one with third prong? (mostly go through the extra work to keep it stock looking). I really can't change the outlet as there is really only two in the whole room and they are on opposite sides. I don't think its the ground for the outlet itself as it happens in two differnet houses, maybe 4 by now.

The only thing I can't figure out is that it only happens with this laptop, I have tried with an ipod, and just other things and never had this problem with them. Could it also be an issue with the laptops ground since the monitor cable clears it up?

TriggerFinger

Snoopdogie187

That was my thought, the laptop would be easier but useless since it only grounds the adapter not the laptop.

If I was to do it on the speakers what should I attach the ground to?

TriggerFinger

Try plugging the speakers on a separate outlet. May an extension cord would help. See this also:

http://alteclansing.custhelp.com/cgi...i=&p_topview=1

Snoopdogie187

I have already done everything the site has said

Monday I will try to run an extenision cord, not home this weekend.

and thsnk you for your help so far