Mixer Electronics Help

[BJMtz]

While in the process of taking out my PA gear out of an old rack and prepping to put it in a new one I heard some movement going on inside of my mixer. I opened up the back and found a little yellow and black piece that had come loose (see pic). First off what is it, and is it something that can be just be reinserted and a little solder applied to keep it in place?

 

[lankyloo]

That is an electrolytic capacitor. A 1,000 uF @ 35 volts to be exact. It looks like the leads (the wires coming out of the bottom) might have come straight off, so it might be possible, but it depends on how the other side of the board looks.

An important thing to pay attention to with these capacitors is that they are polarized, i.e. they have a particular direction they have to be installed. In the picture of the cap, you can see the black strip going down the side with minus signs on it. The lead closest to this side is the negative, while the other is positive. On the board where it came off, you can see that one side has a plus sign on it, right next to the other capacitor. It needs to be installed with the plus lead going to that hole, while the negative lead going to the other hole.

 

[BJMtz]

Thanks so much. I can see what you're talking about with the leads and polarity. Does a piece like this tend to go bad?

 

[moody]

Thanks so much. I can see what you're talking about with the leads and polarity. Does a piece like this tend to go bad?

If not used electrolytic capacitors are 'more' likely to go bad than with regular use.

That said, they have a shelf life of many years. They would probably not have a problem in 20 years of regular use.

 

[lankyloo]

If not used electrolytic capacitors are 'more' likely to go bad than with regular use.

That said, they have a shelf life of many years. They would probably not have a problem in 20 years of regular use.

Yeah, chances are the piece is fine, just some bad soldering to the board which caused it to fall off.