Home Forums Product Discussion & Questions BeoLab Beolab 5 upper bass on-off issue

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  • #47201
    marexy
    SILVER Member

      Hi

      Hope anyone can help. Beolab 5  .SW 2.6 Seeial 21… has

      bproblem that upper bass is going on and off ..at start all is ok after 10 min of playing it is starting to go on ad off.

      Aany idea what can be wrong?

      TThanks

      #47202
      NQVHNWI
      FOUNDER Member

        Are you seeing a flashing red LED?

         

        #47203
        marexy
        SILVER Member

          No Led is green all the time. Totaly normal.

          #47204
          NQVHNWI
          FOUNDER Member

            so you play music…..

            what sort? light orchestral or big heavy boom bass? for 10 minutes?

            no LED indication, then the whole speaker cuts out to standby (firm red LED)?

            or just goes fully dead with no LED change?

            or it continues to play the upper mid, lower treble and upper treble drivers? – just the 15inch sub goes down?

            #47205
            marexy
            SILVER Member

              Led  stay green as normal in play mode. It paly’s normal just upper mid- bas after some time cuts on and off. Like bad solder joit or bad connestion but i allready check that.  Maybe it is a litle sooner if i play loud yes.

              #47206
              NQVHNWI
              FOUNDER Member

                I have known one of my BL5 to trip-out totally (red LED flashing) when playing very loud, very heavy bass.  It is Loudspeaker thermal protection. Fortunately, I did not have the problem if I didnt try to overload it and play normally. This is what the manual says….

                The loudspeaker is equipped with a thermal
                protection system which prevents the units
                from overheating. Should an error occur, the
                system automatically switches the loudspeaker
                to standby – and the indicator light
                flashes red.
                To restore the situation:
                > Disconnect the loudspeaker from the mains.
                > Allow the system time to reset (approx. 3–5
                minutes).
                > Reconnect the loudspeaker to the mains again.

                Should the problem persist, contact your Bang &
                Olufsen retailer.

                Regardless, it sounds like you have an internal fault and should get it checked out by an approved B&O service engineer.

                 

                 

                 

                #47207
                marexy
                SILVER Member

                  I repair  some B&O electronic.  But till now i had non of Beolab 5  to repair and that kind of error may be standard fault here ant there.  That are my personal speakers. Just hope for an answer from someone who has repaired that kind of error as here are some guys with a lot of knowledge on repaires 🙂

                  #47208
                  NQVHNWI
                  FOUNDER Member

                    I repair some B&O electronic……..Just hope for an answer from someone who has repaired that kind of error as here are some guys with a lot of knowledge on repaires

                    Clearly, you have more knowledge than most if you are prepared to go inside a BL5 and make repairs.  I don’t think any advice I can give you – or 99.9% of the other Beoworld members would be useful?  I wish you good luck in solving the problem.

                     

                     

                    #47209
                    marexy
                    SILVER Member

                      Thanks, will try. Some time agoo had been more on forum as now have less and less time. Hope Lee or any other legend can geve some hint ??.

                      #47210
                      BeosoundLondon
                      BRONZE Member

                        Hi,

                        I thought I’d post here given somewhat related. I’ve recently acquired a pair of BL5- does sound great to my ears. I’ve just noticed not much sound seems to come from the dome upper bass driver (the one below the larger acoustic lense) – the dome seems to vibrate a little but I can’t hear much if I put my ear close it it – unlike the tweeter and the 2 other bass drivers. Same thing on both speakers.

                        i was curious if anyone else had the same experience ?

                         

                        #47211
                        NQVHNWI
                        FOUNDER Member

                          Yes, I have.

                          I have found the upper tweeter wears out. You can test by carefully muffling off the lower Tweeter with a soft pillow or cushion and play a high frequency sinewave track through 1 channel. This will identify if you are getting equal sound from each.

                          I found that one upper tweeter had gone – and as a matter of caution (the Tweeters cost relatively little), have the Service engineer replace both. This ensures equal sound and not having to do it again at £200/hr!

                          #47212
                          Beobuddy
                          FOUNDER Member

                            I’ve done dozens off these and the BL5’s are becoming a bit risky, to say the least.

                            @ Marexy. Change both 2 modules at the side of the chassis with each other. If the problem travels from the upper bass to the lower bass, then you know that it is an amplifier problem.

                            If the problem stays at the same driver, then the problem might be the mute section or lies in the filter section.

                            Btw,  tweeters are very costly nowadays.

                            #47213
                            luice
                            BRONZE Member

                              Hi Hope anyone can help. Beolab 5 .SW 2.6 Seeial 21… has bproblem that upper bass is going on and off ..at start all is ok after 10 min of playing it is starting to go on ad off. Aany idea what can be wrong? TThanks

                              Similar issue here, after turn it off when I turn it on yesterday I get same issue.

                              #47214
                              BeosoundLondon
                              BRONZE Member

                                Thanks a lot for this. I think my upper tweeters work great. I just noticed the upper bass / mid range driven (the one exposed at the level of the larger acoustic lense on the large aluminium disk) doesn’t tend to produce much sound even if I put my ear fairly close to it. Much of the speakers sound seems to be coming from the 2 bass drivers and the tweeter.

                                #47215
                                marexy
                                SILVER Member

                                  Double post…

                                   

                                  #47216
                                  marexy
                                  SILVER Member

                                    Hi Beobuddy

                                    Done that..and yes as you guess, it is amp modue fault.

                                    So i am looking for IcePower 1000A Mk2 module.

                                    Or shematics for repair, as Icepower company DK does not  share shematics sadly.

                                    It is interesting that BL5 share some vital parts with BL7.4 and BL1

                                     

                                    #47217
                                    Beobuddy
                                    FOUNDER Member

                                      There are no (public) available diagrams. That makes them hard to repair. If something goes wrong during trying then it can go severe wrong due to the strong power supply driving them.

                                      The modules aren’t manufactured and sold anymore. I don’t expect that they will make another batch off modules due to the limited specifications off these and it probably only will be to replace defective ones.

                                      I’ve managed to fix a number of modules and am working on reverse-engineering back to drawing diagrams for future repairs. I’ve invested in a sincere amount of a money in special power supplies, differential probes, electronic loads, parts, etc. to get them fixed. But, agreed,  with original diagrams life would be much easier.

                                      If you’re searching for a quick fix, then I would suggest that you look for a cheap BL2 and take out the module in that one.

                                      At first glance there seems to be some resemblance but there are difference (BL7-4). I don’t see that with the BL1, other that it has also an ICE powered section for the bass. Mid and high are driven by Class-B amplifiers.

                                      #47218
                                      marexy
                                      SILVER Member

                                        Hi

                                        Thanks

                                        As i am in electronic rapair / not as much as you / but i hope i can repair.

                                        Tweeter have almost same amp as in Beolab 7.4 .

                                        Bass modueles BL5 are 2x IcePower 1000A MK2.

                                        Bass module in BL2 is 500w type.

                                        Tweeters are from ScanSpeak as far as i find out.

                                        upper bass is the same as BL1..if not mistaking.

                                        I have now ordered new IcePower 1000A MK1 And will check if will be ok.

                                        BBiggest issue at BL5 i see on SW -PCB.

                                        Here i can not see any option but only original.

                                         

                                        #47219
                                        Beobuddy
                                        FOUNDER Member

                                          Ad I already mentioned. BL2 and BL5 have the same modules. The 500W modules differ in connection sockets

                                          The lower and upper bass from the BL5 are the same. Both Class D as the bass from the BL1. Design wise different boards and components.

                                          If you’re able to order a new ICE 1000W module, not the stil available 500W, then you probably luckily solved this issue. As changing the modules for the bass made difference.

                                          #47220
                                          marexy
                                          SILVER Member

                                            Ad I already mentioned. BL2 and BL5 have the same modules. The 500W modules differ in connection sockets The lower and upper bass from the BL5 are the same. Both Class D as the bass from the BL1. Design wise different boards and components. If you’re able to order a new ICE 1000W module, not the stil available 500W, then you probably luckily solved this issue. As changing the modules for the bass made difference.

                                            Correct..my mistatke ..BL2 and BL5 have same amp board. Will try new board..hope it helps. But would still like to repair bad one. I change some IC  change some caps , but still same issue. When starting work ok for 5 min. and after that start to cut off and on ..off and on and there is no patern for how long ..strange

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