Please help me pinpoint the problem

[Goochtoucher]

I have had a few threads in the past on here about my wharfedale diamond 10.1 bookshelf speakers because I thought the driver had gone. So I ordered a new one and just installed it, but it still didn't work.
This confused me so I tried to eliminate as many options as possible, I have completely dismantled the speaker at this point, including the small circuitboard inside the speaker (I have no idea what to refer it to or what it does) I would guess that it translates the signal into highs and lows and directs some to the tweeter and some to the bass cone?
The only option left is that the circuitboard itself has a fault. Is this possible?
Is it common? Can I fix it? What should I look for to identify if it is actually the problem?
You have been very helpful in the past, I am hoping someone can shed some light onto any of the questions above.
Thanks

 

[j_garcia]

It is uncommon for a crossover to fail, but by no means impossible, and in this case it definitely sounds like the crossover (board based on what you said) that is bad. I would talk to your dealer or Wharfdale and get a replacement crossover or see if they can send the speaker back in, or replace the whole speaker.

 

[markw]

Assuming you've got two identical speakers, and assuming you've got no problems with going inside them, I'd suggest swapping one component part (woofer, tweeter, crossover) at a time and seeing which one causes the problem to migrate to the other speaker. When it does, you've got the culprit.

What, exactly, is the problem you're trying to isolate?

 

[Goochtoucher]

I will do exactly that, tomorrow I will disassemble the other speaker and swap the drivers, then I can get in touch with wharfedale and let them know of the problem, this also means that the replacement driver is unnecessary and I can check the old one in the speaker that works. See if Wharfedale will do a swap for the driver and give me a working crossover.
Reckon they will be expensive? Also I'm quite interested to know how they might fail, it seems so unlikely to me. Hence why I didn't think about it until now.

 

[DS-21]

Did you test the individual driver with a battery or a musical signal (with the volume way down, especially if it's a tweeter!)?

A cold solder joint or failed component in the crossover and/or quick-disconnect terminal is certainly a possibility. With the faulty joint more likely than a bad part.

 

[TLS Guy]

I have had a few threads in the past on here about my wharfedale diamond 10.1 bookshelf speakers because I thought the driver had gone. So I ordered a new one and just installed it, but it still didn't work.
This confused me so I tried to eliminate as many options as possible, I have completely dismantled the speaker at this point, including the small circuitboard inside the speaker (I have no idea what to refer it to or what it does) I would guess that it translates the signal into highs and lows and directs some to the tweeter and some to the bass cone?
The only option left is that the circuitboard itself has a fault. Is this possible?
Is it common? Can I fix it? What should I look for to identify if it is actually the problem?
You have been very helpful in the past, I am hoping someone can shed some light onto any of the questions above.
Thanks

This is easy to trouble shoot. I think you previously said your problem was no sound from the woofer.

All you need is a 1.5 volt battery and and an ohm meter.

First connect the woofer to the battery. Keep the -ve connected and touch the +ve on and off. Every time you connect the +ve the cone should fly forwards. If not the woofer is not good.

Now connect the crossover and leave the woofer disconnected. In all crossovers there is an inductor, and or inductors in series with the woofer.

Now identify the choke or chokes in series with the woofer on the board.

Now take you ohm meter and connect one probe first to the -ve speaker input terminal and the other to the connection to the -ve cable to the woofer. There should be zero resistance. Next connect one probe to the +ve speaker terminal and the other probe to the first or only choke at the terminal side. You should get 0 ohms. Now connect to the other side of the choke and you should get about 0.2 to 0.3 of an ohm. Now go to the other side of the next choke if there is one, and the resistance should be a bit higher.

Now to the +ve speaker lead and the reading should be the same.

Any interruption (open circuit) or very high resistance, is the point of your fault.

It is very unusual for chokes to fail, more likely you have a dry solder joint on the board and this will identify that. You can then resolder it.

I doubt the cap has developed a short or, your receiver/amp would blow or go into protection.

I suspect your crossover is some sort of variation on this.

 

[Goochtoucher]

I doubt the cap has developed a short or, your receiver/amp would blow or go into protection.

My receiver did recently go into protection mode and I had to send it back. I don't really understand what the quoted sentence means. What is the cap?

Is this fault just a badly built speaker? Or is it something I might have done?
I would just like to know before I bring it up with Wharfedale.

 

[TLS Guy]

My receiver did recently go into protection mode and I had to send it back. I don't really understand what the quoted sentence means. What is the cap?

Is this fault just a badly built speaker? Or is it something I might have done?
I would just like to know before I bring it up with Wharfedale.

In that case it might be the capacitor. The capacitor or capacitors in the woofer circuit filter out the high in addition to the chokes in the low pass filter circuit.

Any component in any electronic circuit can fail any time it feels like it. Since I have rather a lot of equipment, I have a nice service facility here.

If you want, PM me and you can send me that board and I will repair it and return it to you promptly. The only delay would be getting the components, if I don't have them on hand. But that should not take more than 2 business days.

I just need to know that your woofer is working, so do the battery test and post the result.

If the cap or caps have failed in that crossover, then it could easily have caused your receiver to fail. So don't connect that crossover to anything until it gets professional attention.

I can't tell you if it is a badly made crossover until I see it, but most are these days. Everything is cut to the bone in these money grubbing years.

So your equipment is not out of action, for longer than necessary, you might want to send me both crossover. If I determine they are Far Eastern POS, I will upgrade them to made in America standards.

 

[TLS Guy]

My receiver did recently go into protection mode and I had to send it back. I don't really understand what the quoted sentence means. What is the cap?

Is this fault just a badly built speaker? Or is it something I might have done?
I would just like to know before I bring it up with Wharfedale.

In the diagram I sent you C2 would be the offending component and if it failed closed circuit, there will be no sound from the woofer and it will blow your receiver.