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SMGb problem

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One of my SMGb loudspeakers could have been affected by an overload caused by a Perreaux PMF2150 power amplifier. There was smoke emanating from the panel which had me to turn off the power amplifier immediately. The overload could had been caused by a short at the inputs to the power amp due to the messy condition of the room (cables everywhere as I was replacing the existing Fisher integrated with a JVC pre-amp and the above stated power amp)
Both speakers were well protected by the fuse however the problematic one exhibited an absence of high frequency. Could this be due to the damage in the electronics or the ribbon itself? I also realized that the fuse rating of the fuse used in the affected speaker is more than the non-affected one and the smoke could have been originated from one of the components on the electronic board. If it was the ribbon, I do have a repair kit which could come in handy.
I appreciate your advice.
Regards,
Daman

Follow Ups:

Re: SMGb problem - berndt 12:01:03 12/11/06 (11)
You should be able to test continuity with a vom.
No continuity, broken wire or ribbon.
- Re: SMGb problem - ADHuri 08:34:39 12/12/06 (9)
  Berndt,
  I have checked both wire and ribbon and the continuity is intact. The only thing that I could not check precisely are the 2 capacitors which I suspect could be the contributor. Do you have any idea what the values are for both (the big white and the smaller blue)? Do we need to source them from Magnepan or are they available off the shelf?
  Appreciate your input again.
  Thanks and best regards,
  Daman
  - Re: SMGb problem - berndt 12:37:45 12/12/06 (8)
    do the caps have values printed on them?
    Does MUG have a schematic?
    I do not have first hand experience with your model, hopefully a more learned inmate will appear.
    - Re: SMGb problem - ADHuri 02:03:55 12/13/06 (6)
      Berndt,
      I re-checked the continuity again and one stretch of it was open (However I could not make it stick together). The only way to overcome this is to buy a new set of tweeter ribbons and the work could be cumbersome. My choices qre:
      1) Repair both speakers myself by changing the 2 capacitors and replacing both tweeter ribbons (place the order from Magnepan)
      2) Purchase a new set of MMG
      3) Send it to Magnepan for reapir
      What do you think?
      Regards,
      Daman
      - Re: SMGb problem - Rod H. 07:14:04 12/13/06 (5)
        
        In Reply to: Re: SMGb problem posted by ADHuri on December 13, 2006 at 02:03:55:
        
        I've never worked on SMGs before, or even seen them other than in pictures, but I just finished redoing the tweeters on a pair of MG-IIa Maggies. I think they are similar. The first tweeter was difficult and the second was easy. I think it was just a matter of getting the technique down. Now I'm anxious to find some more to repair just for the fun of it!
        Whether you would enjoy this kind of project only you can say.
        Personally, I'd most likely do #1 on your list, and least likely to do #3.
        I doubt the capacitors are the problem, but replacing them with nice poly caps could improve the sound and wouldn't be expensive.
        Rod
        
        Re: SMGb problem - ADHuri 08:23:14 12/13/06 (3)
        
        In Reply to: Re: SMGb problem posted by Rod H. on December 13, 2006 at 07:14:04:
        
        Rod,
        I was wondering if there is a way to join the broken ribbon like soldering it or using a conductive glue (if there is such a thing)? Secondly, I also noticed that the end of the ribbon seemed to be soldered at the terminal post? Did they use normal solder? I hope the repair kit comes with an instruction manual.
        Just want to make sure that I've covered all the necessities if I decided to take the repair path.
        Regards,
        Daman
        
        Re: SMGb problem - rho1 21:53:42 12/13/06 (1)
        
        In Reply to: Re: SMGb problem posted by ADHuri on December 13, 2006 at 08:23:14:
        
        I've heard conductive epoxy has been used successfully. I would give that a shot first.
        
        Re: SMGb problem - ADHuri 01:49:52 12/21/06 (0)
        
        In Reply to: Re: SMGb problem posted by rho1 on December 13, 2006 at 21:53:42:
        
        Dear all,
        Thanks for the advice. I've ordered the repair kit from Magnepan and at the same time would like to try the conductive epoxy.
        Will keep you posted of my progress.
        Regards,
        Daman
        
        Re: SMGb problem - Rod H. 11:22:44 12/13/06 (0)
        
        In Reply to: Re: SMGb problem posted by ADHuri on December 13, 2006 at 08:23:14:
        
        I've read of people using a rear window defroster repair kit to repair the tweeters, but they say it's only a temporary fix.
        The tweeter repair kit from Magnepan should come with special solder for the aluminum wire, and instructions.
        Rod
        
        Re: SMGb problem - ADHuri 07:36:43 12/13/06 (0)
        
        In Reply to: Re: SMGb problem posted by Rod H. on December 13, 2006 at 07:14:04:
        
        Rod,
        Thanks for the advice. I'll order the necessary from Magnepan. The tweeter ribbons definitely need to be changed for both. I am thinking of getting the MMG since this pair has beena around since 1992.
        Will get back to you of my progress.
        Regards,
        Daman
    - Re: SMGb problem - ADHuri 19:43:32 12/12/06 (0)
      Berndt,
      Thanks for the reply. Last question, there are 2 caps with the following inscription;
      - the 1st one is blue in color and has "Richey, 25uF-100V, BBC-9311" and
      - the 2nd is bigger and white in color and has "A2285-100V"
      I would assume that A2285 is capacitor value coding with the "A" indicating temperature or voltage range. How I wish the value of this capacitor is easily identifiable. Do you have any clue?
      Thanks,
      Daman
- Re: SMGb problem - ADHuri 15:38:54 12/11/06 (0)
  Berndt,
  Thanks. I will get back to you on my findings.
  Regards,
  Daman

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