Mystery Component

I’m trying to fix a Pioneer sound bar. It was making a popping noise when I’d turn it on. Other people reported having the same problem, they fixed it by changing out a bad capacitor. In mine, the only part that looks bad to me is what looks like a capacitor but the only markings on it is “220” on the top and on the bottom in very small raised letters it says B28. I found those by removing the component. I drew arrows on the photo to point out a couple dark spots that are not on any of the other identical pieces. Please excuse my ignorance but the only other experience I have with electronics is when I built a color organ from a Radio Shack kit about 40 years ago. Thanks in advance for your response.

Hi Smokey, Welcome!

I believe the part you are pointing to is probably an inductor rather than capacitor. It has a brittle material on the outside that is easily chipped, but this does not affect performance.

I did a little Googling about your issue and most found success by replacing the caps on the left side of your board; specifically, those 4700uF caps. The thread I found had success using the EEU-HD1V472, which is a pretty high quality capacitor. If you want to upgrade to an even higher end part, you might go with the UBY1V472MHL, which is rated for a higher temperature and longer life.

No guarantee that either of these would solve your problem, but this is what several found to work. If you replace the caps, make certain you get the polarity right, as putting them in backwards will guarantee a short life (no pun intended!).

1 Like


Thanks for the response. I guess I’ll solder the inductor back in place and order a capacitor. Or, should I get a replacement inductor too?

The board is glued into the back of the back of the sound bar. Is there a trick for getting it out without breaking something?


It could be a conformal coating which I have a link below that goes into detail of removal Smokey

There is a product for removal as well and that is in the link below.
Also lower in that link are other products to take a look at under the header You Maybe Also Be Interested In.
1 Like

Chris, thanks! I see you’re with DigiKey. I have a feeling I’m going to be getting a lot of bits and pieces from them. I just received a bunch of parts to get me started, a soldering iron, solder, tweezers, wire cutters, solder sucker, wick, a silicone mat… just when I thought I was getting a handle on the clutter in my “man cave.”

1 Like

The problem is exponentially worse when the “Enter an Employee Order” link is accessible. I’d swear that leaving two antistatic baggies unsupervised together overnight causes a dozen more to show up by morning…


Hi Smokey,

Inductors are unlikely to fail, compared to capacitors, and it is much harder to find a suitable replacement for them because their electrical and physical characteristics vary much more.

I would put that back on and replace the caps first.

I agree Rick_1976 :slight_smile:

I checked out your links, I don’t think that’s what I’m trying to get off the board. It’s glued into a chassis making difficult to work on. Attached is a photo of it, you can see the black cement on the edge of the board.

Could be an epoxy, if so yes it will be hard to remove from the board without stressing it and possibly cracking the board. You can google to see what some of the suggestions are for softening or removing epoxy.
One I found but have not tried is below by Bob Vila

How to Remove Epoxy from Plastics or Glass

Epoxy might provide a quick fix for repairing broken plastic pieces or sealing a cracked window pane, but it can be a pain to remove on such delicate surfaces. Simply soak a paper towel in isopropyl alcohol (rubbing alcohol) and rub it on the surface until the epoxy loosens. If the epoxy is still stubborn, a stronger solvent such as denatured alcohol (a solvent commonly used to fuel camping stoves) or paint thinner can also be applied to the area with a cloth to weaken the bond, and a scraper tool can be used to gently pry the epoxy from the surface. Once the epoxy is removed, use a clean, wet rag to remove any remaining solvents from the surface.

Thanks again. I got the board out. I’m not sure if it was the alcohol or just patient prying. The glue didn’t dissolve or become soft but I’m glad just the same. There are a few ribbon connector that are glued into place too. I’m going to leave them because I can work around them.

Sounds good Smokey, hope that repair goes well.