I have experienced this and my solution was to use battery power for when I was connected to the external system (using my laptop as an input device into a sound system).
I have seen others here say that they used a ground lift plug on the power cable (three-prong to two-prong adapter) and that solved the problem for them; I haven't tried this as my laptop is toast and I'm waiting on my new one to arrive
I've been experiencing the same problem on my new 1100 : after maybe 40 min to an hour after the laptop was turned on, the buzzing noise starts up and gets steadily worse 'til I unplug the power supply. The noise is definately related to the amount of harddrive activity going on - i.e. switching powerpoint slides, running a DVD, even moving the mouse has a discernable effect.
Definatley *not* ground loop : hum is nowhere near 60 hz.
About 50% of my purpose for this laptop was for combined audio / video presentations. I've been pretty embarrased the first two times I tried to use it for this purpose, and don't consider that unplugging the power is really a viable workaround : I really don't want to be responsible for having a 100% charged battery every time I get ready to give a presentation.
If Dell seriously has no permanent workaround that will allow me to run external speakers and a power supply at the same time, I'll probably be returning the machine.
Anyone actually *solved* the problem? I mean, does using a two prong plug (non-grounded) work?
Thanks - and especially thanks to any Dell employee who can give me the official line. :)
I am replying to my own Inspiron 8000 thread with an update. Probably applies to all Inspirons.
Definitely a ground loop problem, despite this NOT being a 60Hz signal leakage issue. The RF or audio-F frequency leakage is being carried through the ground pin to the amplifier (and then presented as Martian Morse Code sounds on the speakers).
I have installed a "cheater plug" to lift the three-prong AC power cord above ground (i.e., the ground plug now does not make a circuit, the earth-ground is "floating"). First, I lifted the laptop's ground plug and that eliminated the noise in the speakers. Then I put the laptop back into a grounded outlet and the noise came back. Then I lifted the amplifier's three-prong AC power above ground, and that also eliminated the noise. (This all makes sense to me now when I think about the fact that when the laptop is operating on battery only there is no noise since it is effectively lifted above ground in that configuration too). I am leaving the laptop grounded since that device is $2K in value, but the speaker amplifier is about $50 to replace. Hoping the ground plug is useful to reduce risk of ESD damage, etc. ...
Interestingly, I also opened a problem with the Dell support folks and without even asking me to do the usual "update drivers and BIOS and reinstall the OS" exercise, or, more logically, suggesting I do the above test, they instead immediately arranged for a return-to-depot repair. I suppose paying Air Bourne is cheaper than having a trained technician diagnose the issue and solve it remotely. But I digress! I am now declining the "repair" since I fully expect that this is an inherent design flaw in Dell's audio and power pathways and there is nothing to do about it.
If someone else does a return-to-depot and gets a new system board that fixes (or does not fix) the issue, please post your results to this forum.
I seem to have both problems! I don't seem to have a problem when I connect the laptop from a different ring main, but I think I might be kidding myself. Why? Well I was listening to a CD on the Laptop via headphones and the old noise came back - so no earth loop there - I wasn't plugged in. So I shall be on the phone complaining about "Multimedia" laptops that only do half the story. BTW I've noticed that my one of my headphones seems to dampen the noise so it may be possible to get something to filter out the hum.
Well...well.... Earth Ground is the culprit! indeed a simple 3 way to 2 way conversion and voila noise gone! Not a DELL issue but rather a user's home wiring issue.
We operate a DJ service and the only place that we have experienced this issue is our 9 year old home. Wiring is not my area of expertise but all things being equal clearly the Grounding issue is the root cause of the noise.
I've noticed the problem on two occasions. The first occasion, in my house, there is a substantial reduction in the noise when I use some form of "ground loop work-around". HOWEVER, I've also noticed the problem when the using only headphones...and that was at an INTEL scale lab...where I should imagine they have paid a passing interest in the wiring!
Besides, saying its not DELLs problem cause of you house's wiring is a poor excuse. Why is it that of all the electronic audio equipment I have, the only one that has a problem is the laptop? There is no getting away from the fact it IS a design fault.
THIS GUY IS A GENIUS, HE FIGURED OUT WHAT 3 HOURS W/ DELL SUPPORT COULD NOT FIGURE OUT. THANK YOU!!!! I GOT MY GROUND LOOP ISOLATOR AND LIFE IS SO MUCH BETTER. THANKS ANDREW:
ANDREW WOT WROTE:
You are experiencing ground loop, trust me. Been there but not anymore.
Hi there, took me a long time to solve this prob, but cause I'm becoming an electronics engineer I solved it:),
the noise comes from the "switched" power supply. Although der is no ground attached directly from
power supply to notebook, the noise gets through anyways. It's not really a ground lift, because the freq. is not 50 or us 60Hz, but it comes from the ground. So what I did is simply using some tesa-film or isolate film to isolate the ground of the plug of the power supply, that solves all noisy probs, if not do the same to your amplifier. there might be savetyness reason to do not so, but for the notebooks power supply there is no danger, because some notebooks habe no ground on their power supplies (and no noise). Simply isolating that "dirt" contact helps against that noise on every notebook...for me it works perfect.
ELI_Software
8 Posts
0
October 27th, 2003 00:00
I have experienced this and my solution was to use battery power for when I was connected to the external system (using my laptop as an input device into a sound system).
I have seen others here say that they used a ground lift plug on the power cable (three-prong to two-prong adapter) and that solved the problem for them; I haven't tried this as my laptop is toast and I'm waiting on my new one to arrive
dspman
306 Posts
0
October 27th, 2003 03:00
AnnetteNelson
1 Message
0
October 28th, 2003 02:00
I've been experiencing the same problem on my new 1100 : after maybe 40 min to an hour after the laptop was turned on, the buzzing noise starts up and gets steadily worse 'til I unplug the power supply. The noise is definately related to the amount of harddrive activity going on - i.e. switching powerpoint slides, running a DVD, even moving the mouse has a discernable effect.
Definatley *not* ground loop : hum is nowhere near 60 hz.
About 50% of my purpose for this laptop was for combined audio / video presentations. I've been pretty embarrased the first two times I tried to use it for this purpose, and don't consider that unplugging the power is really a viable workaround : I really don't want to be responsible for having a 100% charged battery every time I get ready to give a presentation.
If Dell seriously has no permanent workaround that will allow me to run external speakers and a power supply at the same time, I'll probably be returning the machine.
Anyone actually *solved* the problem? I mean, does using a two prong plug (non-grounded) work?
Thanks - and especially thanks to any Dell employee who can give me the official line. :)
- Annette
geoperkins
1 Rookie
•
30 Posts
0
October 28th, 2003 11:00
I am replying to my own Inspiron 8000 thread with an update. Probably applies to all Inspirons.
Definitely a ground loop problem, despite this NOT being a 60Hz signal leakage issue. The RF or audio-F frequency leakage is being carried through the ground pin to the amplifier (and then presented as Martian Morse Code sounds on the speakers).
I have installed a "cheater plug" to lift the three-prong AC power cord above ground (i.e., the ground plug now does not make a circuit, the earth-ground is "floating"). First, I lifted the laptop's ground plug and that eliminated the noise in the speakers. Then I put the laptop back into a grounded outlet and the noise came back. Then I lifted the amplifier's three-prong AC power above ground, and that also eliminated the noise. (This all makes sense to me now when I think about the fact that when the laptop is operating on battery only there is no noise since it is effectively lifted above ground in that configuration too). I am leaving the laptop grounded since that device is $2K in value, but the speaker amplifier is about $50 to replace. Hoping the ground plug is useful to reduce risk of ESD damage, etc. ...
Interestingly, I also opened a problem with the Dell support folks and without even asking me to do the usual "update drivers and BIOS and reinstall the OS" exercise, or, more logically, suggesting I do the above test, they instead immediately arranged for a return-to-depot repair. I suppose paying Air Bourne is cheaper than having a trained technician diagnose the issue and solve it remotely. But I digress! I am now declining the "repair" since I fully expect that this is an inherent design flaw in Dell's audio and power pathways and there is nothing to do about it.
If someone else does a return-to-depot and gets a new system board that fixes (or does not fix) the issue, please post your results to this forum.
pkr2000
5 Posts
0
October 28th, 2003 14:00
dspman
306 Posts
0
October 28th, 2003 21:00
There are several threads related to this problem. One of them is:
http://forums.us.dell.com/supportforums/board/message?board.id=insp_audio&message.id=14982
Check it out.
Get Jiggy with
1 Message
0
December 2nd, 2003 01:00
Well...well.... Earth Ground is the culprit! indeed a simple 3 way to 2 way conversion and voila noise gone! Not a DELL issue but rather a user's home wiring issue.
We operate a DJ service and the only place that we have experienced this issue is our 9 year old home. Wiring is not my area of expertise but all things being equal clearly the Grounding issue is the root cause of the noise.
Hope this helps.
BTW, I plug into a $400.00 power bar.
Pat
pkr2000
5 Posts
0
December 3rd, 2003 06:00
I've noticed the problem on two occasions. The first occasion, in my house, there is a substantial reduction in the noise when I use some form of "ground loop work-around". HOWEVER, I've also noticed the problem when the using only headphones...and that was at an INTEL scale lab...where I should imagine they have paid a passing interest in the wiring!
Besides, saying its not DELLs problem cause of you house's wiring is a poor excuse. Why is it that of all the electronic audio equipment I have, the only one that has a problem is the laptop? There is no getting away from the fact it IS a design fault.
shine1479
1 Message
0
January 12th, 2004 17:00
THIS GUY IS A GENIUS, HE FIGURED OUT WHAT 3 HOURS W/ DELL SUPPORT COULD NOT FIGURE OUT. THANK YOU!!!! I GOT MY GROUND LOOP ISOLATOR AND LIFE IS SO MUCH BETTER. THANKS ANDREW:
ANDREW WOT WROTE:
You are experiencing ground loop, trust me. Been there but not anymore.
Thanks to these babies
http://www.xitel.com/product_gli.htm
noise free sound with no frequency loss.
Message Edited by shine1479 on 01-13-2004 04:46 PM
Andrew WOT
194 Posts
0
January 12th, 2004 21:00
You are experiencing ground loop, trust me. Been there but not anymore.
Thanks to these babies
http://www.xitel.com/product_gli.htm
noise free sound with no frequency loss.
Philmar
3 Posts
0
January 12th, 2004 22:00
Hi there, took me a long time to solve this prob, but cause I'm becoming an electronics engineer I solved it:),
the noise comes from the "switched" power supply. Although der is no ground attached directly from
power supply to notebook, the noise gets through anyways. It's not really a ground lift, because the freq. is not 50 or us 60Hz, but it comes from the ground. So what I did is simply using some tesa-film or isolate film to isolate the ground of the plug of the power supply, that solves all noisy probs, if not do the same to your amplifier. there might be savetyness reason to do not so, but for the notebooks power supply there is no danger, because some notebooks habe no ground on their power supplies (and no noise). Simply isolating that "dirt" contact helps against that noise on every notebook...for me it works perfect.
I hope your all happy now!