Defect capacitor on JBL 4344 ??

[Madien3388]

That will do. The temperature on those is set by the tip that is installed.
Should be a "6" if it is 'normal' "7" would be hotter than is normally used
for circuits. If you unscrew the collar at the base of the chrome shaft, the
tube holding the tip slides off. ... look at the end opposite the point.

connection on the back is for grounding... used with sensitive circuits
(not this).

Thanks Grumpy! I've just checked and it is a "7". Is too hot ?
Should I use this or not ?
Merci !
Damien

[Ian Mackenzie]

Unless you are skilled at this type of work you will end up making of what is not really a necessary modification a mess.

Thereis probably more solder in those connectors than you think. The problem then is to apply enough heat to melt all the solder around the male & female to then apply enough pressure to remove the male. That is tricky.

Timing is crucial and you should only do this having a lot of practise

The potential consequence of this is melting the solder on the tracks around the male and pulling the male out of the board if you apply the heat for too long. It may also take several goes to remove the solder.

You may think I am overly cautious but I have seen enough crap modifications & repairs to equipment that were attempted by those with little or know experience to know this is erring on the side of foolish.

You may get lucky and get them out but is it all really necessary?

If you are so worried about it take pics and label all the wires then snip them and take the board to a techician and have it tested and then install new female spades (after the technician has removed the females) or better still just solder the wires to the male luggs).

That as a plan makes a lot more sense. (The females are going to be bent and loose and useless after you finish trying to remove them)

If you were really stuck you could post the HF board to me Air mail and I could test it in exchange for a bottle of good French wine and a calender of the hot French ladies ...LOL. (I have been to France before)

I have the voltage drives of a good HF board in Circuit Tester so it would be straight forward.

The condition of that iron suggest it has been ill used and need cleaning.

Ian

[Hoerninger]

I do strictly second what Ian has said. Soldering is a skill.

I am not out for the calender - France is in the neighbourhood, but a good BORDEAUX ...
____________
Peter

[Madien3388]

Unless you are skilled at this type of work you will end up making of what is not really a necessary modification a mess.

Thereis probably more solder in those connectors than you think. The problem then is to apply enough heat to melt all the solder around the male & female to then apply enough pressure to remove the male. That is tricky.

Timing is crucial and you should only do this having a lot of practise

The potential consequence of this is melting the solder on the tracks around the male and pulling the male out of the board if you apply the heat for too long. It may also take several goes to remove the solder.

You may think I am overly cautious but I have seen enough crap modifications & repairs to equipment that were attempted by those with little or know experience to know this is erring on the side of foolish.

You may get lucky and get them out but is it all really necessary?

If you are so worried about it take pics and label all the wires then snip them and take the board to a techician and have it tested and then install new female spades (after the technician has removed the females) or better still just solder the wires to the male luggs).

That as a plan makes a lot more sense. (The females are going to be bent and loose and useless after you finish trying to remove them)

If you were really stuck you could post the HF board to me Air mail and I could test it in exchange for a bottle of good French wine and a calender of the hot French ladies ...LOL. (I have been to France before)

I have the voltage drives of a good HF board in Circuit Tester so it would be straight forward.

The condition of that iron suggest it has been ill used and need cleaning.

Ian

Many thanks Ian for your help. I am a little lost. You are obviously right. It would be the best to send you the boards, that is very kind of you. And I would be pleased to offer a very good bottle of French wine ans Spanish typical products (my wife is Spanish) (and a good meal too if you were in France).
But it is also risky: I would not like the boards to be lost. I would be in a very bad position if filter parts were missing...

To send you the boards, I would need to cut the wires. But I would like to keep pliers on the cables so that I will be able to replace the filters by new ones in the future (original ones would be carefully stored).
So if I send you the boards (I assume I would have to send you boards of both speakers), would you need to replace the male connectors by another ones and would it be possible to find the same pliers ?
Regarding cables, as some of the cables can not be removed from the cabinets, I would need to find new pliers here in France. And I do not know if we still can find this model of plier and the tool required to add them on the cables...
I am not in a hurry. I want the speakers to be as original as possible, and in perfect condition as they are now.
Damien

[4313B]

According to other pieces of advice, there is some risk to do that because it could damage the PCB due to the high heat of the soldering iron. What do you think ?

What I think is that I just don't have any problems doing this stuff. Yeah, there was a time when I burned a few things up "practicing" but that was a long time ago.

[Madien3388]

I have just found some faston models :

http://www.parts-express.com/pe/show...number=095-286

http://www.gotronic.fr/catalog/conne...ble=faston.htm

I think it is the easier way, much less risky. I cut the wires just after the female fastons and bring it to the pro shop.
I would only need to replace the fastons by new ones. By chance, perhaps the male fastons would not need to be replaced ?

What kind of female fastons do I need : in brass, copper, gold plated, diamond platinium rhodium plated ?

Just for my personal information, what kind of metal shall be used for soldering ? (I have been told that the method was not the same 25 years ago, now you can't use lead, ...)

Whatever the solution will be chosen, I think some people will have deserved a good bottle of French wine ...
Damien

[hjames]

This needs to turn into a basic lesson - How to solder ...


Recommended tip: Get an old junk radio or cassette deck or something similar and practice on that before you go for it on your crossover ...
I'd REALLY suggest you learn on something you don't care much about!

[Madien3388]

Oh no, I have decided not to remove the solder myself. Ian and most of you guys have much more experience than I.
I do not want to damage the speakers.

I'm waiting for some confirmations : is the idea to cut the wire the good one ,
What kind of female fastons should I use ?

Then, I will go to the pro shop and they will do the work. If I see that they are not good enough, I will see that with Ian who nicely proposed to help me...

Many thanks for your help
Kind JBL regards
Damien

[Robh3606]

Hello Damien

Do you have any idea when they were soldered by the previous owner?? The reason I am asking is if it was 10 years ago it would be a solder contaning lead. Within the last couple of years with ROHS in place it would probably be a lead free solder.

You can't mix lead free and lead solders. You will end up with a very brittle solder joint at the interface between them and they will not wet properly. Keep that in mind. If you decide to change out the soldered PCB connectors they will certainly be a Lead solder such as Sn60 or 63. You would need to use a lead solder to replace them because the PCB traces are commonly tinned with Sn60 as an example. Sn60 has a 40% lead content

Not trying to add more confusion but you really should discuss this with whoever does the repair for you. Same thing with the Capacitor. If it needs to be changed you need to use a lead based solder NOT A LEAD FREE solder.

Rob

[Ian Mackenzie]

Many thanks Ian for your help. I am a little lost. You are obviously right. It would be the best to send you the boards, that is very kind of you. And I would be pleased to offer a very good bottle of French wine ans Spanish typical products (my wife is Spanish) (and a good meal too if you were in France).
But it is also risky: I would not like the boards to be lost. I would be in a very bad position if filter parts were missing...

To send you the boards, I would need to cut the wires. But I would like to keep pliers on the cables so that I will be able to replace the filters by new ones in the future (original ones would be carefully stored).
So if I send you the boards (I assume I would have to send you boards of both speakers), would you need to replace the male connectors by another ones and would it be possible to find the same pliers ?
Regarding cables, as some of the cables can not be removed from the cabinets, I would need to find new pliers here in France. And I do not know if we still can find this model of plier and the tool required to add them on the cables...
I am not in a hurry. I want the speakers to be as original as possible, and in perfect condition as they are now.
Damien

L'alternative est que je viennent (par l'intermédiaire des îles grecques) un peu plus tard par année et nous pouvons comparer des produits ! Je connais également quelques bonnes gens audio à Paris. Si vous êtes vous inquiétiez des panneaux obtenant perdus envoyez votre épouse vers le bas ici pour holiday..sh e serez bien occupé ! Ok sérieusement son jusqu'à vous. Vous pourriez envoyer le courrier recommandé de conseils. Plan B. Médecins Who' ; dossiers de croisement de s : J'ai attaché quelques images (j'ai travaillé à ces derniers avant). Si c'est assez de longueur de câble dans le manche vous pourriez dévisser le panneau de croisement ; de l'arrière et du mouvement vers l'ouverture de woofer. Notez que les fils d'entrée sont marqués le & E1 ; E2. Son possible vous devez seulement enlever ces femelles et unclip (6) les agrafes et adoucir le tour la carte plus de pour accéder au dessous de la carte. Là de vous peut gentre enlever la soudure sur les garnitures de soudure du condensateur et l'enlever pour l'essai. Vous pouvez voir des images les connecteurs et il est tout à fait possible la soudure excessive pourrait être mauvais outre du mâle. Mon expérience était les femelles étaient lâche et attemping pour faire à la femelle meilleur convenable était seulement marginalement meilleur. Par conséquent le propriétaire précédent de votre croisement a décidé la soudure elles mais comme vous pouvez voir elle a a a dessiné en arrière si vous avez l'intention d'enlever ou accéder aux conseils. Vous pouvez également pouvoir à la mèche la soudure hors de la femelle mais il est probable vous devra souder de l'autre côté s'ils sont lâches. Je proposerais que le plan ci-dessus B soit la meilleure ligne de conduite de vous décident de faire quelque chose à distance.Je suis sûr que les pinces peuvent être remplacées pendant que j'employais beaucoup pour l'essai de ces croisements. (J'aurai une recherche vous)

The alternative is that I come over (via the Greek Islands) a bit later in the year and we can compare products! I also know a few good audio people in Paris. If you are worried about the boards getting lost send your wife down here for a holiday..she will be well looked after!

Okay seriously its up to you. You could send the boards registered mail.

Plan B.

Doctors Who's crossover files:

I have attached some images (I have worked on these before).

If these is enough length of cable in the loom you could unscrew the crossover panel; from the rear and move towards the woofer opening.

Note that the input wires are labeled E1 & E2,. Its possible you only need to remove those females and unclip the (6) clips and gentle turn the Pcb over to access underside of the Pcb. From there you can gently remove solder on the solder pads of the capacitor and remove it for testing.

You can see from the images the connectors and it is quite possible the excess solder could be wicked off the male. My experience was the females were loose and attemping to make the female fit better was only marginally better. Hence the previous owner of your crossover decided the solder them but as you can see it has a draw back if you intend to remove or access the boards. You may also be able to wick the solder out of the female but it is likely you will need to solder then again if they are loose. I am sure the pliers can be replaced as I used a lot for testing of these crossovers. ( I will have a look for you)

I would suggest the above Plan B is the best course of action of you decide to do something remotely.

[Ian Mackenzie]

Roberto makes a good point.

[Ian Mackenzie]

I still think this is all a lot of meddling for what is most likely nothing.

If the leaking(?) capacitor was off its value there would be some audiable channel mismatch between channels. But as I said earlier unless you match the L pads of both channels exactly there is nothing to get too excited about. The positions on the L pads are not accurate) and good matching of both channels is important if the speaker are to image at all properly. A 1/2 a db in level here and 1/2 a db there across the mid/horn and slot means you could have a 1 or more db variation between channels. This will cause not only a shift in the images (loss of focus) but the tonal balance will be also different. I found the 3145 improved quite a bit from being a good loudspeaker to an excellent loudspeaker when you take care to obtain very close balance. Its a bit like sharpening up an axe.

The point being the potential issue of the capacitor is moot compared to proper adjustment of the L Pads.

Ian

[Madien3388]

I have already said it a large number of times but many thanks for your patience and help, I really appreciate. it helps me a lot.

I would like to try the plan B but I will let a professional do the job. My only concern is to remove the filter from the cabinets; for this, I have to remove the solder on the fastons with only 2 possibilities :
- 1) I try to remove the solder from the fastons myself, but it is very risky
- 2) I cut the cables, just after the female fastons and bring the PCB to a professional : he will test the capacitor and will remove the solder on the female fastons. I would only need to add new female fastons myself on the cables.

For example, Chas doesn't have solder on its 4345 fastons and he doesn't have any issue. I would really like to have fastons plugged in the male fastons without any solder (it is the more practical solution if I want to replace the filters in the future).
If you think this solution is a good one, I will do that. Ian, if you could advice me someone in Paris who could do this job carefully, I will feel better. It is more and more difficult to find good and honest persons in audio highend those days.
I would only need to find this rare person, who will do the solders properly, to be sure that the PCB & male fastons could be keep safe.
Damien

[Ian Mackenzie]

Pm sent.

[Ian Mackenzie]

I have already said it a large number of times but many thanks for your patience and help, I really appreciate. it helps me a lot.

I would like to try the plan B but I will let a professional do the job. My only concern is to remove the filter from the cabinets; for this, I have to remove the solder on the fastons with only 2 possibilities :
- 1) I try to remove the solder from the fastons myself, but it is very risky
- 2) I cut the cables, just after the female fastons and bring the PCB to a professional : he will test the capacitor and will remove the solder on the female fastons. I would only need to add new female fastons myself on the cables.

For example, Chas doesn't have solder on its 4345 fastons and he doesn't have any issue. I would really like to have fastons plugged in the male fastons without any solder (it is the more practical solution if I want to replace the filters in the future).
If you think this solution is a good one, I will do that. Ian, if you could advice me someone in Paris who could do this job carefully, I will feel better. It is more and more difficult to find good and honest persons in audio highend those days.
I would only need to find this rare person, who will do the solders properly, to be sure that the PCB & male fastons could be keep safe.
Damien

For clarity what I was saying in the previous post is that there is less risk in unsoldering only (2) of the fastons E1 & E2 than all the others.
Then you would need to remove the capacitor or unsolder at leat one end and then test it with a multi meter that has capacitance range (Most do).
This could be done on site without removing all the other fastons given the caveats I mention earlier and would be least invasive or the original work.

However the previous owner has done some invasive work (solder fastons) and you may find more once you turn the pcb over. Therefore you need to decide of you want to return the crossover to original factory condition without solder on any of the fastons or just explore the capacitor?

One point I will make is that capacitors are strange devices and a simple measure of capacitance may not tell you everything about its condition.

As this capacitor is not in series with the driver if it is intermitantly faulty you may not be aware of this. This type if fault is more common in high voltage circuits like in Televisons and RF devices.

So you have (2) two options, try and do an site inspection and a simple test of the capacitor OR snipe all the wires and take it to someone and have the females removed and replace the females on the sniped wires on return of the HF board for re installation.

One question, Are all the other fastons on the woofer/mid board also soldered?

One of the problems with this type of activity is the more you look the bigger the job becomes and what might appear a simple exercise can become a headaches...(trust me I know)

The reference may actually reside in Zurich..I cannot remember.

In the Link below are some knowledgable Forum members, most of them are in Europe.

If you go to the front of the thread you can see the location of some members. rs237 in the green shirt is quite unassuming but very clever in my view and has a good sense of humour. There are other members who might be able to assist.



http://www.audioheritage.org/vbullet...&postcount=187


Ian