Identify voltage rating of a SMB electrolytic cap

Replacing some defective SMB capacitor that does not have a clear voltage rating. The text on top of the cap is 3 lines, 8B, 47, JZA. 47 is 47uf, but don’t know what 8B and JZA means. Tx

Hello Pmeebers,
This post explains how to ID specs from capacitor part markings.

What type and size of the capacitor are you looking for?

Thank you Nathan for the information. I am in the process of “re-capping” my Bose Wave radio". These were outfitted with faulty SMb capacitors from the factory. This has affected thousands of radios. Bose has since stopped making these radios and are no longer warranted. Radios consist of 2 main circuit boards. I am presently working on one of the circuit boards. I have ordered replacement caps from DigiKey and was in the process of validating the size, voltage ratings for all the parts received. That is when I noticed that one cap had this unknown marking. Other 47uf caps are clearly marked @ 6.3 volts. There are 15 caps on this one board, and 35 caps on the second board. When the first board was done, I was going to order caps for the second board, now in the process of identifying value, voltage rating and lead polarity. So to answer your question, I don’t know the voltage rating of one cap, it is 47 uf and that is all I know, hence the question. Tx again for your reply. Pat

Since this is consumer audio gear there is an easy way to figure out what voltage to buy when you don’t have the original spec.

Choose the highest voltage that fits in the same space on the PCB.

A higher voltage virtually always gives better performance in audio gear and the capacitor lifetime goes up too.

1 Like

Hello,

The link provided does show what the voltage code is. I would say if the JZA is on the bottom. The voltage would be the 6.3v like this link: SMT Electrolytic Capacitor with no Voltage Rating - Passives / Capacitors - Electronic Component and Engineering Solution Forum - TechForum │ Digi-Key (digikey.com)
This was in the link that Nathan provided. Though I also agree with Hutch. You know the 47uf. You can look through the list of options with tha value . You can narrow down by the smd 47uf . Click in stock and apply filters. Then measure what you have and narrow down by size. Hopefully this new link helps.

1 Like

Thanks again for such great information. Most people who are repairing these are using much bigger (physical) size than original. To look at a repaired board, it looks quite messy as most coaxial caps are soldered and then bent over. I am attempting to add a pic to this post, in the hops that will better explain the original problem. I am confident that I have the solution and will proceed. The additional link was very helpful. Tx Pat

1 Like

Thank you for your follow up.

If you could kindly provide the cap diameter and height sizing we could find similar caps that would fit in the same spot.