freshly recapped 586 with no sound from its woofer

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LordTaifleh
Berichten: 21
Lid geworden op: 15 mei 2015, 23:34

Hi all,

i’ve had this pair of philips mfb 586 that were waiting to have their caps replaced.

One of the speakers always had a fault, where sometimes, the big speaker would not output any sound but sometimes do.

After finishing the recapping, this has gotten worse instead of better, which i had hoped.

which parts should i look at to find the fault?

the feedback part seems to work, as the membrane gives the same sound when i knock on it while switched on.
snameroc
Donateur
Berichten: 9249
Lid geworden op: 01 mei 2010, 13:45

You meen that the feedback also works when there is no sound of the woofer?
LordTaifleh
Berichten: 21
Lid geworden op: 15 mei 2015, 23:34

i mean, that the woofer membrane is stiff when power is turned on, regardless of the working state of the amp that sporadically showed the error. so i think the correction circuit seems to work ok.

i'm hoping for for feedback of some of the enlightened people that post in this forum and who may have seen a similar problem

If i'm not being clear enough, please bear with me and ask more questions so i can clear things up

cheers
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Remi
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Berichten: 12256
Lid geworden op: 16 jun 2005, 21:04
Locatie: Didam

not clear to me for sure. Stiff membrane?
can the conus move? how about the relay, did you replace it? It might be a good idea, or try to clean the contacts inside the relay. They are known to become poor resulting in shabby sound for mostly the tweeter but sometimes the woofer is also affected.
"Hoezo nu wel genoeg? D'r is toch nog plek!" jaja, waar dan? "Ha! d'r kan nog wat in de auto!"
Forumnaam
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Berichten: 1090
Lid geworden op: 21 aug 2021, 10:12

Maybe a video of the fault/happening with sound on makes it more clear what the problem is?
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Thomas
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Lid geworden op: 16 jun 2005, 15:55
Locatie: Lochem, Gelderland
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You may have to clean the relay contacts or replace the relay.
Thomas Baur
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LordTaifleh
Berichten: 21
Lid geworden op: 15 mei 2015, 23:34

The woofer is toast. There is no connection whatsoever between the positive and negative..
LordTaifleh
Berichten: 21
Lid geworden op: 15 mei 2015, 23:34

I was able to resolder the wire of the voice coil to the flex cable and now it works again!
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