Martin Logan Sequel II dead panels

[Z571848]

Thanks for the link X83. Btw, what could possibly go wrong with these coils...they look pretty sturdy? Also, if I have to replace one, how will I know what size/kind?

 

[Z571848]

X83

Btw, I wasn't clear about your last message on how to check the bias boards. ..if replacing these last crossover parts does not work, I'll ask for further clarification...I'm better with visuals and very basic explanation.

 

[X83]

Thanks for the link X83. Btw, what could possibly go wrong with these coils...they look pretty sturdy? Also, if I have to replace one, how will I know what size/kind?

I believe it's the L1 0.8-ohm 2.7mH inductor that's fried and the enamel insulation coating can only withstand around 200-degrees before it short circuits.

ERSE-EQ

 

[Z571848]

X83

Thanks for that information. ..I'll see what happens when I replace those resistors before I order the inductor...or do you think I should replace that before for fear of damage to the new parts?

 

[bolserst]

I wouldn't recoat the panels unless it's necessary. A good way to see if your bias & panels are working well is to hook up a 1kV 0.1uF capacitor with a neon bulb in parallel connection between the high voltage red wire out of the bias board to the panel in series.

@Z571848,
In case circuit diagrams make more sense than words to you, the links below might be useful.

Neon bulb circuit and brief description on how/why the neon bulb flashes -
http://www.diyaudio.com/forums/planars-exotics/76222-esl-build-thread-12.html#post952272

Neon bulb circuit as implemented in Quad ESL63 and trouble shooting hints -
http://www.diyaudio.com/forums/planars-exotics/153773-esl-technical-questions.html#post1958015

 

[Z571848]

hook up a 1kV 0.1uF capacitor with a neon bulb in parallel connection between the high voltage red wire out of the bias board to the panel in series.

Okay

What do you mean when you say "in parallel and in series" in the above statement? I understand the terms but not as they relate to the bias boards leads and panel leads. I drew a very basic diagram and I will try to attach it if I can figure out how. ...even so, it sounds like I only need the red wires from the board and the panels...what happens to the black wires and the blue from the panel in you test described in previous comments. I really need this explained without electrical engineering terminology for me to understand. I'm sure that this will not impress anyone but it will really help me. [image][/image]

 

[Z571848]

Here is my basic drawing. ...please let me know what I'm missing. Thanks.

 

[bolserst]

Here is my basic drawing. ...please let me know what I'm missing. Thanks.

I thought the words alone might be confusing...you have the neon lamp and capacitor in series not parallel in your drawing.
Did you look at the diagrams in the links I put in post#65?

Attached is a corrected version of your drawing, and the schematic diagram from the first link for comparison.

NOTE: You will need to have the step-up transformer wired up to the bias board and panel for the panel to charge and the neon bulb flash.

 

[Z571848]

Okay, I get it now. Thanks bolserst and X83. So, I just want to make sure. ..I only use the red wires no black or blue. ..they just do not get connected to anything? Also, I don't need the big transformer or the crossover board at all? If I have it right, are cap and neon lbulb something I can pick up at Radio Shack or a more dedicated electronics store for more instant gratification?

 

[bolserst]

So, I just want to make sure. ..I only use the red wires no black or blue. ..they just do not get connected to anything? Also, I don't need the big transformer or the crossover board at all?

Re-read post#68 and you will find your answer:
"NOTE: You will need to have the step-up transformer wired up to the bias board and panel for the panel to charge and the neon bulb flash"

Basically, you need everything wired up to the panel like you were going to play music thru them, and the bias supply powered up.

are cap and neon lbulb something I can pick up at Radio Shack or a more dedicated electronics store for more instant gratification?

Unfortunately, Radio Shack does not carry a suitable capacitor at local stores. You would need to mail order it.
I purchase parts from Mouser or Allied Electronics as they are local to me.
I know X83 recently purchased neon charge indicator parts for his Monoliths.
Perhaps he can share where he ordered them from.

Back in the early 90s I wired up a neon charge indicator to quick-disconnect terminals.
I still have it in my test kit...very handy for troubleshooting ESLs that don't have one built in.

 

[Z571848]

Well folks...I'm done with this project. I received the resistors I was waiting for ...installed them and got same results. I'm tired and I don't think I can go any further at this time. I want to thank you all for the help and education. ..it was a great learning experience. Maybe some day if the right opportunity comes up I'll continue but until then. ..I'm done.

 

[tyu]

All re-paires... Speakers,Amps what ever...... are Process of alimiantion................even when you have done this type of work befor..... for years maybe.....at can be tuff..........only way i ever got this type of work fig out was to know when to walk away......a new day can be a good thing!

ESL are some of the best speaker ever made.............but can be a pain in the ***.!?@#...
So you gave it your best shot...an we all learned something more about some of the best ESL ever made in the US.........

good luck..an happy hoho to all...........

 

[Andersonix]

Why was it suggested that the resistors be moved from the secondary side to the primary side? I thought it was 'standard' practice to place a resistor in series with the primary?

Why don't you just remove the toasted crossover board and keep the step up transformer with the R4 100K-ohm 50W & R5 5K-ohm 20W resistors on the secondary side of the circuit and use an active crossover?
.

Okay they have both been damaged and you should use a lower ohm value on the other side of the transformer.

I would order two Dale NH-25 25-Watt 1-ohm 1% resistors and two Dale RH-50 50-Watt 20-ohm 1% resistors.

You can install them both on the primary side of the transformer and it will make wiring them much easier.

 

[aekalman]

Why was it suggested that the resistors be moved from the secondary side to the primary side? I thought it was 'standard' practice to place a resistor in series with the primary?

I was wondering this myself ... my SLIIs have experienced almost the same exact failure, and I will convert them to biamp with active xovers ... I'll make a replacement PCB to keep things tidy ...