Help with crossover repair on MK S–55 tri-pole speaker

[oriddlero]

The speaker was originally working fine and I just noticed during my set up in a new house that it was no longer producing sound. I've completely disassembled the speaker for troubleshooting and attached some photographs including the requested front/back photographs of the crossover cup. Below are some additional troubleshooting findings:

• All four drivers are within 4-8 ohm resistance. Each driver was additionally click/pop tested with 1.5 VDC
• every solder joint on the board was probed and tested for continuity and tested good
• every ceramic resistor was tested within printed tolerance.
• All four of the inductors were tested good for continuity
• I have not tested the capacitors yet because they were not bulging and I did not feel like de-soldering all of them to test them individually (yet)
• crossover cup was tested for continuity between the speaker wire posts and the internal spade connectors

One thing I did notice is the blue circuit labeled 2.0K/ 50v tested to only 4 ohms. I am not familiar with this design of circuit, is it a resistor? If so should it be testing 2k ohms, not 4? It also does not seem to have a wattage rating on it if it is in fact a resistor =[

Thank you in advance for any help you can provide!

 

[Arouse1973]

The yellow component measuring 4 ohms is a capacitor. It might have something connected across it which is why it reads a low value. Can you see by the PCB traces if its connected to anything else?
Adam

 

[oriddlero]

Thank you Adam. I found it strange that the capacitor was not marked for polarity. So what would you say the value of this cap is if i need to replace it?

BTW, my name is also Adam =]

 

[Arouse1973]

Hi Adam .
its a metalised capacitor and has no polarity. I must admit It is often printed on them in terms of pico Farads but this is 2.0. Could be 2uF, not sure. The K is the tolerance and is 10%. Others might know, let me get back to you on that. Meanwhile you could lift one leg of the cap out of circuit and measure it.
Adam.

 

[ver chan]

you can see the print in the PCB it was labeled as C3- probably that is capacitor

 

[ver chan]

i guess the 4 ohms is just a resistance of other component, try to unsolder one pin of this component to check if this capacitor is leaked, shorted (partially or fully shorted), or open.

 

[Arouse1973]

Hi Adam

I am pretty sure this is a 2.0 uF 50 V metallized Polypropylene capacitor. You should be able to find a replacement easily on the net if you need to. Try some audio component suppliers.

Thanks
Adam