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Defective male power connector on computer speakers

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boomer#...@none.com

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Dec 1, 2016, 5:03:12 AM12/1/16
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I have an inexpensive pair of powered computer speakers. I didn't pay
much for them. but they have worked pretty well for the last year or so.
All of a sudden they became touchy and would not turn on, or would shut
themselves off.

Bending and twisting power cord makes it work (maybe), for a short time.
The power comes from a wall transformer labeled output 7.5V 350MA. The
plug on the cord end that plugs into one of the speakers looks like
this:
http://www.jameco.com/Jameco/content/walladapter-fig5.jpg
(probably not the same dimentions)

I put a meter on the plug, wiggled the cord and there is no loose
connection. I opened the speaker and found that if I wiggle the male
plug socket soldered onto the circuit board, I make and break the
connection. Using the ohm scale on my meter, it appears the outer shell
terminal is the one at fault. (Not the center pin). Pushing a thin
jewlers screwdriver under that plug seems to maintain a connection.

In brief, that male connector has a bad connection and needs to be
replaced.

I am aware these plugs come in many sizes, and finding the right one
could be a challenge. That eliminates shopping online. This leaves me
with only Radio Shack, meaning I'll have to take the transformer along
and see if anything fits.

My question is DO THEY MAKE INLINE MALE PLUGS FOR THESE KINDS OF PLUGS?
Im sure finding one that will fit on the circuit board will be near
impossible. But I could easily run 2 wires out the back and solder on a
male inline plug.

If all else fails, I will probably just cut the female plug off the cord
and solder the cord right into the speaker. I'm not willing to spend
much money or a lot of time on this project, but they work fine othewise
so I want to fix them.

By the way, is there a name for this type of plug?



Ralph Mowery

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Dec 1, 2016, 9:44:54 AM12/1/16
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In article <j8tv3cdtvo2gqts28...@4ax.com>, boomer#6877250
@none.com says...
>
> I have an inexpensive pair of powered computer speakers. I didn't pay
> much for them. but they have worked pretty well for the last year or so.
> All of a sudden they became touchy and would not turn on, or would shut
> themselves off.
>
>
> In brief, that male connector has a bad connection and needs to be
> replaced.
>
> I am aware these plugs come in many sizes, and finding the right one
> could be a challenge. That eliminates shopping online. This leaves me
> with only Radio Shack, meaning I'll have to take the transformer along
> and see if anything fits.
>
>
They are called coaxial power plugs. I bought some male and female
pairs a while back off ebay for only a few dollars. Maybe you can just
buy a pair of them to get the sizes to match and replace both pieces.

Tim R

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Dec 2, 2016, 8:34:12 AM12/2/16
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On Thursday, December 1, 2016 at 5:03:12 AM UTC-5, boomer#...@none.com wrote:
>
> If all else fails, I will probably just cut the female plug off the cord
> and solder the cord right into the speaker. I'm not willing to spend
> much money or a lot of time on this project, but they work fine othewise
> so I want to fix them.
>
> By the way, is there a name for this type of plug?

Might be easier to go back with BNC, if there's room in the speaker.

MJC

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Dec 2, 2016, 9:49:53 AM12/2/16
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In article <b92ac96a-306f-4b6e...@googlegroups.com>,
timot...@aol.com says...
BNC for power?

Mike.

Ralph Mowery

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Dec 2, 2016, 10:00:43 AM12/2/16
to
In article <MPG.32ab9a6...@news.plus.net>,
gra...@mjcoon.plus.com says...
>
> In article <b92ac96a-306f-4b6e...@googlegroups.com>,
> timot...@aol.com says...
> >
>
> >
> > Might be easier to go back with BNC, if there's room in the speaker.
>
> BNC for power?
>
> Mike.

Probably way too hard to get the wires attached to the male part of a
BNC. I sort of thought phono plug but that would leave the male part
where it could short out to something when unplugged if the male was
hooked to the power supply.

Ebay has lots of the coaxial type power plugs and sockets for a few
bucks. Just buy a matching set so they will fit without any problems.


Michael Black

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Dec 2, 2016, 12:31:29 PM12/2/16
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But if you use shielded cable, BNC wouldn't be too hard.

I thought I'd seen them used as HV connectors in power amplifiers
somewhere.

Michael

Tim R

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Dec 2, 2016, 12:43:06 PM12/2/16
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I've seen them used for power somewhere. Maybe it was a lab for some school course.

I've had second thoughts though. A BNC is a pretty firm connection. If somebody trips over the cord it will yank the guts out of the speaker. Then I thought of a phono plug, but yeah that might have the problem with the short.

Could go to some kind of automotive molex? maybe? My thought is there are plenty of inexpensive and available connection options that I would use before hardwiring this. For one thing, wal-warts do go bad. The other is the trip hazard problem.

Or, what about an F connector? Plenty of those around.

Ralph Mowery

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Dec 2, 2016, 12:50:18 PM12/2/16
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In article <alpine.LNX.2.02.1...@darkstar.example.org>,
et...@ncf.ca says...
>
>
> >
> But if you use shielded cable, BNC wouldn't be too hard.
>
> I thought I'd seen them used as HV connectors in power amplifiers
> somewhere.
>
> Michael

BNC are made for specific sizes of coax cable. Try and put any othe
size on and it is very difficult. The center pin would probably push
back unless it is some of the ones that are for samll cable and the
pinis fixed ans soldered to. I doubt the small computer speaker power
cube would have any shielded wiring and hard ot put that on a wall cube.

I doubt the BNC is used on power amplifiers as the voltage rating is
only 500 volts peak.


Dave Platt

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Dec 2, 2016, 1:31:28 PM12/2/16
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In article <b91ed541-d9fe-41cf...@googlegroups.com>,
Tim R <timot...@aol.com> wrote:

>Could go to some kind of automotive molex? maybe? My thought is there are plenty of inexpensive and available
>connection options that I would use before hardwiring this. For one thing, wal-warts do go bad. The other is the
>trip hazard problem.
>
>Or, what about an F connector? Plenty of those around.

Consider Anderson PowerPole connectors. They've replaced Molex
throughout much of the amateur-radio community - they're more rugged,
even the little 15-amp contacts will handle more current than you'll
need, and they pull apart and reconnect cleanly and easily.

There's a de facto standard in the ham community for a two-contact
configuration for ham radios operating on 12-14 VDC. If your speaker
uses a different voltage, you could pair up the contacts differently
(I use a "top and bottom" vs. "side by side" orientation whenever I do
this).




whit3rd

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Dec 2, 2016, 1:36:42 PM12/2/16
to
On Thursday, December 1, 2016 at 2:03:12 AM UTC-8, boomer#...@none.com wrote:
> I have an inexpensive pair of powered computer speakers. ...[ wilth loss of power]
> I put a meter on the plug, wiggled the cord and there is no loose
> connection. I opened the speaker and found that if I wiggle the male
> plug socket soldered onto the circuit board, I make and break the
> connection.

> In brief, that male connector has a bad connection and needs to be
> replaced.

No, it seems that the printed wiring board has a crack and needs repair.
Or, the solder joint to the connector that connects it to the printed wiring board
is faulty, and requires a bit of solder flux and reheating.

Get a lens out, and examine carefully.

Tim R

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Dec 3, 2016, 11:42:58 AM12/3/16
to

Maybe we're over thinking this.

How about a pair of binding posts on the speaker, and strip the ends of the power supply wires?

micky

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Dec 3, 2016, 4:37:19 PM12/3/16
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In sci.electronics.repair, on Thu, 01 Dec 2016 04:02:02 -0600,
At hamfests over the last 4 years, I think it's more than one person who
has been selling a little transparent bag of 7 power plugs, all
different, and I those 7 make up 99% of all the plugs used.

At hamfests one bag was only $2 so I bought 3 on the theory I'd need 3,
all the same size.

But that doesn't mean you'll be able to find this. You very often see
more than one vendor at more than one hamfest in more than one state
selling the same stuff, but how often that happens nationwide, or where
you and I are, I don't know. And a lot of hamfests are so small no one
is selling this.

This is no good because it's $30. FWIW the plugs are longer than my $2
set. :-)
https://www.amazon.com/Generic-Straight-Universal-Connector-Notebook/dp/B00DC1PCJ8
This is $6 plus shipping:
https://www.altex.com/6-Power-Cable-with-Assorted-Coax-Plugs-48-400-P143451.aspx


A more likely bet and something always available online is that there
are also universal power adapters, that have a range of voltages from 3
or 4.5 up to 9 or 12, and they have SEVEN or so power plugs on the end
all attached at once. Make sure you get one with enough power for yoru
speakers because they come in 500ma and 1000mamp iirc. Even the big one
is no more than $10.

I have 3 or 4 universal ones of various ratings and I use them to
figure out the minimum voltage I need to make something work, if it's
not labeled, and to use temporarily until I find or make a one-size
adapter. But sometimes temporarily drags on for years, like for my
router. I used a universal temporarily until I found an exact
replacement on ebay. That worked for a year or two before it burned out
in the same way the first one did. Someone, maybe here, said they were
known to be unreliable. 5 minutes after the second one broke, I was
back to the universal, which was still lying on my desk behind the
monitor.

Make sure the voltage and amperage goes high enough.

$18 for 1300 ma but you can probably do better
https://www.amazon.com/PowerLine-90367-Universal-Power-Adapter/dp/B00CWR39TI
I hate to push walmart but this at least looks like the same thign, $13
https://www.walmart.com/ip/Original-Power-Powerline-1300-mA-Universal-AC-Adapter/16778839
Microcenter has more than one model, not especially cheap.

FINALLY THIS is what I meant $8.35
http://www.ebay.com/itm/AC-DC-Wall-Power-Charger-ADAPTER-Universal-3-4-5-6-7-5-9-12V-Power-supply-2-5A-/301595192644?hash=item4638796d44:g:ROkAAOSwv0tVLb2D

Well I like the ones where they are all wired in at the same time,
including to replace a 9-volt battery, but maybe you don't care.

Ron D.

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Dec 4, 2016, 9:26:05 PM12/4/16
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You might just bag it and replace the entire adapter. See: http://www.powerstream.com/ac-07505.htm

Anything 7.5 V and greater than or equal to 350 mA will work.

There is a little ICON on the adapter that can tell you if center is positive. You have to have the correct polarity.

The URL, I mentioned has an adapter set and a reverse polarity adapter available if you need it.

5.5/2.1 and 5.5/2.5 are vary common sizes. The problem is the 5.5/2.5 fits on the 5.5/2.1 receptacle.

With a caliper, you can measure the OD in mm. The ID can be measures using a known receptacle and/or a drill bit. For the 5.5/2.1 & 5.5/2.5, I use two of the known receptacles. If they both fit, it's the 5.5/2.1.

There are plenty of sizes to choose from: https://en.wikipedia.org/wiki/Coaxial_power_connector

boomer#...@none.com

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Dec 8, 2016, 7:22:05 AM12/8/16
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On Sun, 4 Dec 2016 18:25:58 -0800 (PST), "Ron D." <Ron.D...@gmail.com>
wrote:

>You might just bag it and replace the entire adapter.

Why?
The adapter works fine, it's the female plug on the speaker thats bad.

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