Help: Non-working Speakers

D

Darren Harris

Guest
Someone asked me to attempt to fix an audio problem with a unique
video game system that has internal speakers that do not work at all.
But the system has connections for external speakers. And only one of
the two external speakers will work depending on what game PCB is
plugged into the system. http://www.massystems.com/SuperNova.html

I don't think the problem stems from the game PCBs that hook up to the
system, and was hoping that someone can tell me how to confirm that
all involved leads are carrying signals(using a multimeter).

I need to test the wiring for the internal speakers, as well as any
external speakers that can be plugged into the system.

Thanks a lot.

Darren
 
Does anyone know how to make sure the correct signals are traveling
through all leads and junctions? All I know is that there is no audio
for the internal speakers.

Thanks.

Darren Harris
Staten Island, New York.
 
On 14 Jul 2004 16:57:10 -0700, Searcher7@mail.con2.com (Darren Harris)
wrote:

Someone asked me to attempt to fix an audio problem with a unique
video game system that has internal speakers that do not work at all.
But the system has connections for external speakers. And only one of
the two external speakers will work depending on what game PCB is
plugged into the system. http://www.massystems.com/SuperNova.html

I don't think the problem stems from the game PCBs that hook up to the
system, and was hoping that someone can tell me how to confirm that
all involved leads are carrying signals(using a multimeter).

I need to test the wiring for the internal speakers, as well as any
external speakers that can be plugged into the system.

Thanks a lot.

Darren
Click to expand...
OK, I'll bite on this one. I don't think you are going to have
much luck with the multimeter approach, unless you have
some control over what the signals are. A loud, steady tone
or buzz might register, but many game effects are too
transient to see on a meter. A scope is the tool of choice
for stuff like this, especially because the problem may be
farther upstream than the speaker leads. It might be a
bad amp or volume control, in which case the levels will be
much too low for anything but a scope.

You mention that one speaker works under some conditions.
Here's an idea: Get a pair of headphones and put a resistor
in series with the hot leads, about 1K to 10K range, just so you
don't blast your ears out. Then check how that sounds on
the working channel at various points in the chain from the
amp to the speaker. Compare to the non-working channel.

My first suspicion in this sort of thing is upstream of the
speakers, like the power amp or volume control (if any).
The headphone tester might not be sensitive enough there,
but worth a shot. Then consider unsoldering and swapping
inputs to the power amp channels... if the other speaker
starts working, the problem was upstream of the amp.
If not, the amp channel is probably bad.

Hope this helps!




Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
 
OK, I'll bite on this one. I don't think you are going to have
much luck with the multimeter approach, unless you have
some control over what the signals are. A loud, steady tone
or buzz might register, but many game effects are too
transient to see on a meter. A scope is the tool of choice
for stuff like this, especially because the problem may be
farther upstream than the speaker leads. It might be a
bad amp or volume control, in which case the levels will be
much too low for anything but a scope.
Click to expand...
I used my multimeter to check for continuity between the harness edge
connector that the PCBs plaug into and the system speakers along with
the external speakers. I'd like to diagram it with ASCII, but wouldn't
know how to do that here, because it would just show up all garbled.
But I can send a diagram showing the set-up(and continuity) to anyone
who wants to see it.

The system has the red and white outputs for speakers. As well as some
sort of conversion PCB for playing those arcade games(made to be used
with arcade monitors) on a PC monitor, and an S-Video output also.

You mention that one speaker works under some conditions.
Here's an idea: Get a pair of headphones and put a resistor
in series with the hot leads, about 1K to 10K range, just so you
don't blast your ears out. Then check how that sounds on
the working channel at various points in the chain from the
amp to the speaker. Compare to the non-working channel.
Click to expand...
I would know how to do all that. But four different game PCBs(which
equate to four different amps) were tried. If the audio of all four
work when wither oif them are plugged into an acutal arcade cabinet
should they all work or not work with this particular system?

My first suspicion in this sort of thing is upstream of the
speakers, like the power amp or volume control (if any).
The headphone tester might not be sensitive enough there,
but worth a shot. Then consider unsoldering and swapping
inputs to the power amp channels... if the other speaker
starts working, the problem was upstream of the amp.
If not, the amp channel is probably bad.
Click to expand...
I'll ahve to go back there and see what I can find out.

Thanks a lot.

Darren Harris
Staten Island, New York.
 
Okay.

The problem is definitely not the amps or speaker controls on any of
the four game PCBs. I tested each of these boards in a full sized
arcade cabinet, and the audio works perfectly on all of them. The
external speakers also work perfectly when hooked up to a stereo.

That means the problem is somewhere in the *harness* of the "MAS
system", from the PCB connector(where leads for positive and negative
audio, as well as ground originate) to the (red and white)speaker
outputs. There is nothing else in the loop. So now I'm wondering if
the system was wired incorrectly.

I'm going to try resoldering what is there and perhaps swap some wires
for new ones, but can anyone point me to a diagram that shows how
things should be wired between the connector(that attaches to the game
PCBs) and the speaker outputs, along with how ground is supposed to
hooked up also? I'm a newbie at this, and really know nothing).

THanks a lot.

Darren Harris
Staten Island, New York.
 
Darren Harris wrote:

Okay.

The problem is definitely not the amps or speaker controls on any of
the four game PCBs. I tested each of these boards in a full sized
arcade cabinet, and the audio works perfectly on all of them. The
external speakers also work perfectly when hooked up to a stereo.

That means the problem is somewhere in the *harness* of the "MAS
system", from the PCB connector(where leads for positive and negative
audio, as well as ground originate) to the (red and white)speaker
outputs. There is nothing else in the loop. So now I'm wondering if
the system was wired incorrectly.

I'm going to try resoldering what is there and perhaps swap some wires
for new ones, but can anyone point me to a diagram that shows how
things should be wired between the connector(that attaches to the game
PCBs) and the speaker outputs, along with how ground is supposed to
hooked up also? I'm a newbie at this, and really know nothing).

While you're waiting, you could always trace the actual wires.
Click to expand...

Good Luck!
Rich
 
While you're waiting, you could always trace the actual wires.
Click to expand...
I have no idea what you mean by that.

I know where each wire originates and ends, but like I said, I need to
find out if it is wired correctly.

Darren Harris
Staten Island, New York.
 
On 28 Jul 2004 06:54:04 -0700, Searcher7@mail.con2.com (Darren Harris)
wrote:

While you're waiting, you could always trace the actual wires.

I have no idea what you mean by that.

I know where each wire originates and ends, but like I said, I need to
find out if it is wired correctly.

Darren Harris
Staten Island, New York.
Click to expand...
Have you compared where each wire originates and ends with where each
wire *should* originate and end?

d
Pearce Consulting
http://www.pearce.uk.com
 
Have you compared where each wire originates and ends with where each
wire *should* originate and end?
Click to expand...
There is no way to do that if I don't now where each wire is supposed
to go. So far no one has been able to tell me.

1) At one end of the audio harness is the PCB connector. A)Pin-10 =
positive audio, B)Pin-L = negative audio, and C)Pin-27 = audio ground.

***Three wires are supposed to originate at those three pins. But how
are they supposed to run to the following?

2) On the other side are the speaker, and also the two outputs for
external speakers.

If anyone wants a jpeg diagram that illustrates what I just said,
please let me know.

Thanks a lot.

Darren Harris
Staten Island, New York.
 
Darren Harris wrote:

While you're waiting, you could always trace the actual wires.

I have no idea what you mean by that.

I know where each wire originates and ends, but like I said, I need to
find out if it is wired correctly.
Click to expand...
You know where each wire _is supposed to_ begin and end, but do the
physical wires actually complete the circuit? By "trace the wires"
I mean, physically, get down, cut the tie wraps, and visually examine
the wires themselves. Look for breaks, shorts, anything abnormal.

A cold solder joint on an edge connector would give you those
symptoms, and it takes some careful inspection to spot them.

But from what you've described, the only thing _left_ is the
actual wires (and their connections.)

Good Luck!
Rich
 
Rich Grise <null@example.net> wrote in message news:<Tg_Nc.35267$qT3.30073@nwrddc03.gnilink.net>...
Darren Harris wrote:

While you're waiting, you could always trace the actual wires.

I have no idea what you mean by that.

I know where each wire originates and ends, but like I said, I need to
find out if it is wired correctly.


You know where each wire _is supposed to_ begin and end, but do the
physical wires actually complete the circuit? By "trace the wires"
I mean, physically, get down, cut the tie wraps, and visually examine
the wires themselves. Look for breaks, shorts, anything abnormal.

A cold solder joint on an edge connector would give you those
symptoms, and it takes some careful inspection to spot them.

But from what you've described, the only thing _left_ is the
actual wires (and their connections.)
Click to expand...
I know all that. This is what I've been saying.

I've inspected all of the wires already, and have a crimp tool, wires,
and pins for swapping out for new ones. But none of this makes a
difference if it is not wired correctly to begin with.

***I just need someone who knows how speakers are *supposed* to be
wired to show me so I can determine if this System's audio is wired
correctly.

Darren Harris
Staten Island, New York.
 
I've inspected all of the wires already, and have a crimp tool, wires,
and pins for swapping out for new ones. But none of this makes a
difference if it is not wired correctly to begin with.

***I just need someone who knows how speakers are *supposed* to be
wired to show me so I can determine if this System's audio is wired
correctly.

Darren Harris
Staten Island, New York.
Click to expand...
To better illustrate how the audio portion is wired:

***Starting at the PCB connector, there are three leads/pins.

A) A ground pin(for audio). Goes directly to white external output.
From this point another wire goes to the positive audio of the
system's speaker.
B) A Positive(+) audio pin. Goes directly to the red external output.
C) A negative(-) audio pin. Goes directly to a soldered area *in
between* and shared by both the red and the white external outputs.
From this point another wire goes to the negative audio of the
system's speaker.

Can anyone tell me if all this is correct? If it is, I'll have to swap
out all the wiring and put in new wires the same way.(And/or get a
different speaker).

Thanks a lot.

Darren Harris
Staten Island, New York.
 
Darren Harris wrote:

To better illustrate how the audio portion is wired:

***Starting at the PCB connector, there are three leads/pins.

A) A ground pin(for audio). Goes directly to white external output.
From this point another wire goes to the positive audio of the
system's speaker.
B) A Positive(+) audio pin. Goes directly to the red external output.
C) A negative(-) audio pin. Goes directly to a soldered area *in
between* and shared by both the red and the white external outputs.
From this point another wire goes to the negative audio of the
system's speaker.
Click to expand...
I can't figure out what you're trying to describe here. What does
"shared by both the red and the white external outputs" mean, for
example? What are "A ground, a positive audio, a negative audio"
pins? Do you have any documentation that tells you which two of
these are supposed to be connected to the two speaker terminals?

Do you have any kind of wiring diagram or anything? The
audio outputs should go to the speakers. What aren't you telling
us?

Thanks,
Rich
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top