London Art Posted June 3, 2024 Posted June 3, 2024 Hello, I am a new member but from your site I was able to find the clues to the information that I needed to repair my Mission MS8 subwoofer. The content on your website showed an image of the internal pcb with exactly the same component C11 that had burnt out in my unit. I was able to repair my unit and I thought I would share my findings. Browsing the internet I discovered that the Mission MS8 Rev 1 electronics is exactly the same as the JBL PB10 subwoofer. https://www.manualslib.com/manual/781313/Jbl-Powerbass-Pb10.html Accessing the pcb is fairly straight forward. Disconnect the power. Remove only the outer screws from the control back-plate and use a wide flat blade (wallpaper scarper) to gently ease the control back-plate from its foam padding. The burnt out component is C11 which is a 100nF 50v Temperature rating 105 degrees C capacitor. I also found that the adjacent capacitor C10 was also faulty. This is a 10uF 100V Temperature rating 105 degrees C Non-Polarized (Bi-Polar) electrolytic capacitor. ( I noticed that a photo on the web that shows this C10 capacitor missing. Iit was present on my unit and its in the parts list so as to why is shown missing is unclear.) The other capacitor that also proved faulty was C32 10uF 35V Temperature rating 105 degrees C electrolytic capacitor. The manual also provided basic instructions for checking the internal amplifier using prior to powering if you have a DVM. If you are handy with a soldering iron (or you know someone else who is) and you have one of these units not working or not working very well and you want to spend a few pounds on the components then you may be able to bring a dis-guarded unit back to life. My main reason for attempting the repair was that I did not want to spend nearly 500 pounds on a new sub-woofer. I realize that this unit is quite old now but if it still works why throw it away! Hope this helps someone else. Regards Arthur 1
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