not exactly an electronics repair.. need advice

[kneedeep]

I'm a total noob where electronics is concerned and looking for some basic info.

I have a computer speaker, two way, with a bass speaker that just quit working. The tweeter still works and the bass driver looks ok - the cone is intact.

inside the enclosure are three components, I'm guessing a crossover and maybe a resistor and a capacitor, or ???.

I would like to find replacement parts to see if I can make it work again, the problem is I know I need to discharge a capacitor before handling but so far I am unable to identify what the components are.
One is a 1&1/2" black cylinder, the other two are cylinders - 1/2" or less, one black one blue, both with leads on one end. The larger part has leads on both ends.

They were hot glued into the speaker case with a bit of insulation, which is obscuring what is printed on them (I can see some printing but there are no color codes on any of them - so there's no capacitor??). Once I get them out I should be able to identify and find replacements but I don't want to get bit or damage anything in the process.
I would imagine the voltage is quite low but really have no idea.
Any advice on how to handle them?

 

[OLIVE2222]

Hi kneedeep,

Sharp pictures of the components can help us a lot to identify them. Indeed the involved voltages are very low, no need to worry about at all.

Olivier

 

[kneedeep]

Hi kneedeep,

Sharp pictures of the components can help us a lot to identify them. Indeed the involved voltages are very low, no need to worry about at all.

Olivier

Thanks, good to know.
I'll disassemble and take some pics.

 

[kneedeep]

After learning how to use the camera and resize images, i think I have some sharp photos if I didn't screw up the links....
For the last one, I can scrape a bit more to get more of the hot glue off if necessary.

The big black one:
http://imagebin.org/190814
Maybe the damaged component?
http://imagebin.org/190811
http://imagebin.org/190810
http://imagebin.org/190809


The blue one:
http://imagebin.org/190804
the other side:
http://imagebin.org/190805

The black one - it doesn't look too good either:
http://imagebin.org/190818
the other side:
http://imagebin.org/190807

Thanks for your time.
Curt

 

[jackorocko]

The big black one looks like an inductor, a coil of wire around a ferrite rod. The other two look like capacitors, the black one is a 16V 22uF. The blue one is a 33uF 16V cap. Both look to be Alum electrolytic caps as well. Should be easy to replace these.

Are you sure the coil on the speaker itself has not been damaged? Maybe you should check to see that it is not blown.

 

[OLIVE2222]

That's it! just take care about the cap's they are not polarized type. The inductor is almost bullet proof compared to the crappy electrolytic caps.

Olivier

 

[duke37]

Before dismantling, check the resistance across the input wires, it should be a few ohms. If it is open circuit, check the resistance across the bass speaker, it should be a few ohms (same as input). If you have a stereo pair, compare the two.
Measure the resistance across the inductor, it should be very low.

 

[kneedeep]

The big black one looks like an inductor, a coil of wire around a ferrite rod. The other two look like capacitors, the black one is a 16V 22uF. The blue one is a 33uF 16V cap. Both look to be Alum electrolytic caps as well. Should be easy to replace these.

Are you sure the coil on the speaker itself has not been damaged? Maybe you should check to see that it is not blown.

Well, it looks like you've saved me some money and time. I connected the driver directly to another amp and got sound out of the tweeter and nothing from the bass driver... so I guess it's toast?

How would I go about checking the other components?

 

[jackorocko]

I would do what duke says and check the resistance across the speaker coil. Make sure that the coil is still intact.

 

[kneedeep]

Before dismantling, check the resistance across the input wires, it should be a few ohms. If it is open circuit, check the resistance across the bass speaker, it should be a few ohms (same as input). If you have a stereo pair, compare the two.
Measure the resistance across the inductor, it should be very low.

All I have for an ohm meter is an automotive (analog) model. Would this be sufficient?.. or should I get my hands on a digital (adjustable) type?

 

[Resqueline]

An old analog automotive resistance meter should do just fine, but your test with an amp connected directly to the drivers sounds quite conclusive to me.
Checking capacitors is a bit more involved.

 

[kneedeep]

An old analog automotive resistance meter should do just fine, but your test with an amp connected directly to the drivers sounds quite conclusive to me.
Checking capacitors is a bit more involved.

I'm afraid you're right but I'm hoping (against hope) that I can revive it. I'll be hard pressed to find a driver to fit the plastic molding in the enclosure, let alone match the one in the other speaker.

 

[Resqueline]

Sometimes it's the flexing wires between the frame and the membrane that breaks. This is sometimes possible for a layman to replace.