Announcement

Collapse
No announcement yet.

Troubleshooting Behringer Eurolive B215d PA speaker

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Troubleshooting Behringer Eurolive B215d PA speaker

    Hi Everyone,

    I volunteered to tear apart a Behringer B215d Active PA speaker that my gym uses for workout music and instructor microphones. I'm a mechanical engineer by trade, so the finer points of PCBs and circuit tracing still elude me. I got the amplifier and power supply out of the cabinet and I'm pretty sure the power supply section is OK. The fuse is fine, and I get 120VAC between the leads going to the amplifer board from the power supply. I haven't ripped it apart further to start poking and prodding at all the other parts on the amplifer board, but I know I'll get confused quickly since I've never tried to troubleshoot IC chips, MOSFETs, or anything more complex than some resistors and capacitors.

    The only thing that sticks out to me visually is this piece... It seems like this is another style of capacitor or small inductor? It looks like it may have taken some thermal damage compared to the neighboring component that looks identical (except for the fancy colors that I associate with metal annealing). If anyone's got any advice, that'd be great! If not, no worries... There's already a new PA speaker being ordered, I'm doing this for fun and to maybe score a backup speaker should something else happen.

    Thanks in advance!

    Click image for larger version

Name:	20180104_213127-1.jpg
Views:	1
Size:	216.2 KB
ID:	1358690

    Voxel Down Firing with Dayton SA70
    Translam Subwoofers - The Jedi Mind Tricks
    The Super Bees - Garage 2 way
    SevenSixTwo - InDIYana 2018 Coax

  • #2
    It may be a cap, but impossible to say for sure from the end view.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

    Comment


    • #3
      Originally posted by billfitzmaurice View Post
      It may be a cap, but impossible to say for sure from the end view.

      Thanks Bill! I thought about how unclear that picture was as I was drifting off to sleep last night. I'll add a better one this evening. In the meantime, I've been sleuthing around the web and found that Behringer (or at least SOMEONE) has posted the circuit diagram for the Eurolive B215d series online (http://schems.com/bmampscom/behringe...nger_B215D.pdf).

      Looking at some of the other pictures I took last night, the component that looks healthy and identical to the one that I suspect of thermal damage is listed as "L2" on the board, and shows up as "L2 BEAD" on the diagram. Googling that suggests the part is an axial ferrite bead choke, but I don't see any indication of what size or specs one would use to replace it. For reference, I've included a screenshot of the circuit diagram. L2 BEAD is higlighted yellow, L3 BEAD is Cyan, and R13 is green, just included for a reference. The component next to the suspect thermal damage part is R13, but the picture cuts off the R.

      Click image for larger version

Name:	L2 cropped.png
Views:	1
Size:	733.3 KB
ID:	1358725 Click image for larger version

Name:	B125d circuit snap.png
Views:	2
Size:	52.4 KB
ID:	1358726


      Does anyone have experience with these diagrams to know where I ought to look for more info on this component? Alternatively, what would I measure to know what size of component to replace this with?

      Thanks!
      Keith
      Attached Files
      Voxel Down Firing with Dayton SA70
      Translam Subwoofers - The Jedi Mind Tricks
      The Super Bees - Garage 2 way
      SevenSixTwo - InDIYana 2018 Coax

      Comment


      • #4
        Those Inductor components( L2, L3) overheating are potentially indicitive of a problem elsewhere so don't jump to any conclusions, I'd suspect a short in one of those capacitors or resistors just downstream(C25.C32, etc), maybe a short in the rectifier itself(D10), or even a problem further down stream. Have you tested the voltage rails in this diagram to see if they are up to spec?
        Paul O

        Comment


        • #5
          Originally posted by Paul O View Post
          Those Inductor components( L2, L3) overheating are potentially indicitive of a problem elsewhere so don't jump to any conclusions, I'd suspect a short in one of those capacitors or resistors just downstream(C25.C32, etc), maybe a short in the rectifier itself(D10), or even a problem further down stream. Have you tested the voltage rails in this diagram to see if they are up to spec?
          Hi Paul, thanks for the response! I learned to suspect other issues as you mentioned after I spoke with some electrical engineers at work. I have not dug further into that amp board yet, so I'm not sure if I'm getting proper rail voltage or not Beyond neighboring caps, there's a series of FETs right next to this ferrite bead that might also be an issue if I'm looking for sources of unexpected heat. If one of them shorted out and burnt up, that might explain the issue. I don't have a FET tester, so if they are cheap enough, that would be a replace and pray kind of fix. We'll see if I keep going. Replacement amp boards are only $100, so if I'd need several components I'd probably be better off buying the whole board. Sent from my SM-N900V using Tapatalk
          Voxel Down Firing with Dayton SA70
          Translam Subwoofers - The Jedi Mind Tricks
          The Super Bees - Garage 2 way
          SevenSixTwo - InDIYana 2018 Coax

          Comment


          • #6
            Unlikely those caps would short, I would see if that hot choke un-soldered itself and make sure all voltage rails
            are there and around the same voltage of diagram, you can read the voltages from ground (- of C27) to J3, J4, J5, J6.
            Careful those caps will hold a charge after it is unplugged a zap the poo out of you!!!
            Guess xmax's age.

            My guess: 15. His grammar is passable. His trolling is good.

            Comment


            • #7
              Originally posted by xmax View Post
              Unlikely those caps would short, I would see if that hot choke un-soldered itself and make sure all voltage rails
              are there and around the same voltage of diagram, you can read the voltages from ground (- of C27) to J3, J4, J5, J6.
              Careful those caps will hold a charge after it is unplugged a zap the poo out of you!!!
              Thanks xmax! I haven't had time dedicated to this little side project since my last post. I prefer to keep all my body functions performing at the right times... so I will take great care to only touch things with my multimeter probes!

              In addition to checking rail voltage, the first thing on my list is to try is to replace the FETs that are underneath the heat sinks near the toasty choke. Those seem like the most likely source of errant heat in the event of a component failure. I'll just need some luck to find the FET identifier and hope it's a cheap part to replace. If it's gonna cost me $60 in FETs just to see if that works, then I'll scrap the whole idea and move on.
              Voxel Down Firing with Dayton SA70
              Translam Subwoofers - The Jedi Mind Tricks
              The Super Bees - Garage 2 way
              SevenSixTwo - InDIYana 2018 Coax

              Comment


              • #8
                Any chance the FETS you are referring are rectifiers? do they have a D# next to them? Fets can be tested with a multi meter in diode mode if they are fets.
                If those voltage rails are all there and the problem is deeper in the amp and you are busy making those dope Coaxials... Save it for a electronics dork!
                Guess xmax's age.

                My guess: 15. His grammar is passable. His trolling is good.

                Comment


                • #9
                  Originally posted by xmax View Post
                  Any chance the FETS you are referring are rectifiers? do they have a D# next to them? Fets can be tested with a multi meter in diode mode if they are fets.
                  If those voltage rails are all there and the problem is deeper in the amp and you are busy making those dope Coaxials... Save it for a electronics dork!
                  Hey man, there's always a chance that I'm full of BS when it comes to circuit boards

                  If the issue is really in the power supply rather than the power amplifier section, then there are rectifiers shown by D9 or D10 in the previously attached picture and circuit diagram. To me, a bum diode makes as much sense as the FETs being an issue... and it looks like they are physically close to one another on the circuit board, so thank you!

                  Googling the rectifier part numbers (D10 = MUR1620CT / D9 = MUR1620CTR) looks like those are $1.50 parts. When I get that heat sink off I can confirm whether those are the diode rectifier parts rather than the FETs from the amplifier section ( FYI Listed as IXTP50N25T at $4.10 each).

                  This side project definitely isn't taking quality time from the SevenSixTwo coaxials! It's always a question of how much time to I really have on a given evening!
                  Voxel Down Firing with Dayton SA70
                  Translam Subwoofers - The Jedi Mind Tricks
                  The Super Bees - Garage 2 way
                  SevenSixTwo - InDIYana 2018 Coax

                  Comment


                  • #10
                    Yup D9 and D10 look like they will have 3 pins and probably look like a Mosfet. Any meter has a diode setting
                    you should see like .3-.7 chances are if it is bad it will be open or shorted. also see if that choke and the solder
                    joints survived too.
                    Guess xmax's age.

                    My guess: 15. His grammar is passable. His trolling is good.

                    Comment

                    Working...
                    X