03-12-2019, 01:28 AM
|
#16
|
|
Nifty Access Guy
Join Date: Jul 2003
Location: Newbury Berks UK
Posts: 10,365
Thanks: 555
Thanked 948 Times in 897 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Mark_
Then again this is a good reason not to earth to your plumbing.
|
>>>I've connected an old speaker wire between a lug on the PC for attaching some sort of locking mechanism and the radiator<<<
Oops!
__________________
Code:
|||||
@(~Ô^Ô~)@
-------------oOo---U---oOo-------------
| |
| Uncle Gizmo |
| |
| |
| Get $20 worth of "Nifty Code" |
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
| Ooo |
|_________________ooO____( )________|
( ) ) /
\ ( (_/
\_)
|
|
|
|
03-12-2019, 03:00 AM
|
#17
|
|
AWF VIP
Join Date: Jul 2013
Location: UK - Wiltshire
Posts: 6,437
Thanks: 166
Thanked 1,738 Times in 1,707 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Uncle Gizmo
>>>I've connected an old speaker wire between a lug on the PC for attaching some sort of locking mechanism and the radiator<<<
Oops!
|
I think (but am not qualified) that it's part of build regulations to have your plumbing earthed in the UK...
__________________
If we have helped please add to our reputation - click the scales symbol on the left, tick 'I approve' and leave a comment.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
|
|
|
|
03-12-2019, 03:03 AM
|
#18
|
|
AWF VIP
Join Date: Jul 2013
Location: UK - Wiltshire
Posts: 6,437
Thanks: 166
Thanked 1,738 Times in 1,707 Posts
|
Re: Hum Hum Hum!
The distinct tingle is a probably a result of the earthing being poor, allowing a potential difference (voltage) to build up.
In theory once earthed the problem will dissipate (pun intended)
__________________
If we have helped please add to our reputation - click the scales symbol on the left, tick 'I approve' and leave a comment.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
|
|
|
|
03-12-2019, 02:27 PM
|
#19
|
|
Newly Registered User
Join Date: Apr 2010
Location: Central California
Posts: 680
Thanks: 9
Thanked 56 Times in 54 Posts
|
Re: Hum Hum Hum!
My guess is that the power supply is not properly grounded (or the motherboard has a bad ground connection). Hums in speaker systems a lot of times(back in the day) were caused by a floating ground.
|
|
|
|
|
03-12-2019, 03:00 PM
|
#20
|
|
Super Moderator
Join Date: Jan 2009
Location: NSW Australia
Posts: 11,717
Thanks: 105
Thanked 1,512 Times in 1,425 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Uncle Gizmo
I've connected an old speaker wire between a lug on the PC for attaching some sort of locking mechanism and the radiator.
|
There is something wrong with the Earth connection from you power point, the lead or the computer power supply.
Quote:
|
As I was preparing the end of the copper wire, I had attached one end to the PC, I was holding the other end ready to attach it to the radiator when I got the distinct tingle from it. In other words the PC case has some sort of voltage associated with it.
|
There are capacitors between the live and chassis, and the neutral and chassis designed to bypass high frequency interference to ground. If the chassis is not earthed the bypass capacitors will put small but detectible voltage onto the chassis.
Wherever the earthing has failed, you need to get this fixed.
|
|
|
|
|
03-12-2019, 03:03 PM
|
#21
|
|
Longboard on the internet
Join Date: Sep 2017
Location: Not the middle of no where, but I can see the road to it from my house.
Posts: 2,112
Thanks: 20
Thanked 400 Times in 393 Posts
|
Re: Hum Hum Hum!
I'd also open the case and make sure nothing is loose and touching the case. Stray live connection can cause immense problems.
|
|
|
|
|
03-12-2019, 03:26 PM
|
#22
|
|
Super Moderator
Join Date: Jan 2009
Location: NSW Australia
Posts: 11,717
Thanks: 105
Thanked 1,512 Times in 1,425 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Mark_
I'd also open the case and make sure nothing is loose and touching the case. Stray live connection can cause immense problems.
|
If that were the problem there would be more than a tingle on the case. 
I used to work as a electrical/electronics tech in the renewable energy industry and have first hand experience with bypass capacitors putting small voltages onto unearthed equipment.
|
|
|
|
|
05-01-2019, 02:47 PM
|
#23
|
|
Happy Retired Curmudgeon
Join Date: Feb 2001
Location: Suburban New Orleans, LA, USA
Posts: 14,737
Thanks: 93
Thanked 1,718 Times in 1,590 Posts
|
Re: Hum Hum Hum!
Quote:
|
I believe I need to refrain from asking what you've chosen for your seat...
|
Cotton-blend pants on naugahyde seats leads to static buildup. In which case a poor ground will allow you to discharge it in the MOST unexpected ways. But sorry, no cameras were rolling at the time.
__________________
I'm a certified grandpa (3 times now) and proud of it.
Retired over one year and survived being home all day with the wife. She must really love me.
If I have helped you, please either click the thanks or click the scales.
|
|
|
|
|
05-01-2019, 03:33 PM
|
#24
|
|
AWF VIP
Join Date: Oct 2018
Location: Ontario, Canada
Posts: 1,232
Thanks: 10
Thanked 232 Times in 220 Posts
|
Re: Hum Hum Hum!
maybe put a voltmeter between the end of the wire and the radiator?
__________________
Sometimes I just roll my eyes out loud...
Windows 10; Office 365 (Access 2016)
|
|
|
|
|
05-01-2019, 04:21 PM
|
#25
|
|
Nifty Access Guy
Join Date: Jul 2003
Location: Newbury Berks UK
Posts: 10,365
Thanks: 555
Thanked 948 Times in 897 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Micron
maybe put a voltmeter between the end of the wire and the radiator?
|
Won't that knacker the volt meter?
Sent from my SM-G925F using Tapatalk
__________________
Code:
|||||
@(~Ô^Ô~)@
-------------oOo---U---oOo-------------
| |
| Uncle Gizmo |
| |
| |
| Get $20 worth of "Nifty Code" |
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
| Ooo |
|_________________ooO____( )________|
( ) ) /
\ ( (_/
\_)
|
|
|
|
|
05-01-2019, 04:50 PM
|
#26
|
|
AWF VIP
Join Date: Oct 2018
Location: Ontario, Canada
Posts: 1,232
Thanks: 10
Thanked 232 Times in 220 Posts
|
Re: Hum Hum Hum!
No, not unless you SEVERELY over load it, which I doubt you could. While I know of one case where one blew up on somebody, that was from putting several thousands of volts into one that shouldn't have had more than about 300 impressed on it. I was a diesel mechanic in a previous work life and did quite well on the electrical side of things, especially on exams. What you'd be doing is checking the potential between the pc case and some ground, which isn't really any different than if you put across a battery (DC) or across your household electrical outlet. The meter won't conduct current unless you've got it set to measure current, so don't do that if it's a multi-meter. Otherwise, as I said, you're just measuring potential. If you get 50V, that's how much is leaking across that wire. NOTE 30VAC is enough to kill you, so I suggest you don't screw around with this issue. If you've got leakage to ground from a power supply or something on that pc case you are playing with danger. Usually these things don't get better - they get worse.
EDIT
Do I have to point out that you don't hold the metal prongs of the meter leads in your hands?? It should go without saying that you need to be insulated, but assumptions can be dangerous.
|
|
|
|
|
05-02-2019, 12:13 AM
|
#27
|
|
Nifty Access Guy
Join Date: Jul 2003
Location: Newbury Berks UK
Posts: 10,365
Thanks: 555
Thanked 948 Times in 897 Posts
|
Re: Hum Hum Hum!
Quote:
Originally Posted by Micron
I was a diesel mechanic in a previous work life
|
Well I'm blowed! Same here! I worked on lorries for several years (for The Americans, lorries is an English term for a lorry? In America that would be a truck! Possibly!)
I was also pretty good at sussing out the electrical faults. Mind you I had the opportunity to look under a HGV bonnet recently and there was this big box under there, I think it said something like danger 7000 volts! It was something to do with the electronic diesel injection system. Made me realise that I probably shouldn't consider tinkering with someone's lorry, not without getting a refresher on health and safety!
__________________
Code:
|||||
@(~Ô^Ô~)@
-------------oOo---U---oOo-------------
| |
| Uncle Gizmo |
| |
| |
| Get $20 worth of "Nifty Code" |
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
| Ooo |
|_________________ooO____( )________|
( ) ) /
\ ( (_/
\_)
|
|
|
|
|
11-05-2019, 10:35 PM
|
#28
|
|
Happy Retired Curmudgeon
Join Date: Feb 2001
Location: Suburban New Orleans, LA, USA
Posts: 14,737
Thanks: 93
Thanked 1,718 Times in 1,590 Posts
|
Re: Hum Hum Hum!
If you had a tingle when touching a wire attached to the chassis, you have a flawed tower. Something isn't right inside the box. If the case isn't grounded then you have a potential danger. That wire you mentioned that leads to the radiator will probably provide a decent ground, but the fact that you needed one is not good.
Did you buy that mini-tower or build it? If you bought it, you might wish to talk to the tech service department of the seller and ask if they have been having ground fault problems in that particular model. If you built it, something wasn't connected correctly.
__________________
I'm a certified grandpa (3 times now) and proud of it.
Retired over one year and survived being home all day with the wife. She must really love me.
If I have helped you, please either click the thanks or click the scales.
|
|
|
|
| Thread Tools |
|
|
| Display Modes |
Rate This Thread |
 Linear Mode
|
|
All times are GMT -8. The time now is 05:26 AM.
|
|
