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Re: 8 years later [message #95150 is a reply to message #93455] Sun, 30 January 2022 09:54 Go to previous messageGo to next message
panduro is currently offline  panduro
Messages: 32
Registered: March 2013
Location: denmark, european union
Baron
Out of space, yes the midhorn driver and Wiring is fine, atm left speaker is running, low and high over the passive xover, midhorn wires directly to second Channel on amp and xovered through Minidsp shd.

Yeah would prob be a relatively simple job, but I'm completely clueless with crossovers, and I don't know what to look for especially since it looks like schematic of the xover is with a different layout than the pcb my crossover is made on.

I'll look into shipping during coming week.


Ben
Re: 8 years later [message #95153 is a reply to message #95150] Sun, 30 January 2022 16:42 Go to previous messageGo to next message
Barryso is currently offline  Barryso
Messages: 160
Registered: May 2009
Master
Post some high resolution photos of the crossovers. Maybe one of us can spot something.
Re: 8 years later [message #95199 is a reply to message #93455] Sat, 05 February 2022 15:45 Go to previous messageGo to next message
panduro is currently offline  panduro
Messages: 32
Registered: March 2013
Location: denmark, european union
Baron
Thx for the answers.

Hope following pics does the trick, if not let me know what part of pcs would help.

/forum/index.php?t=getfile&id=3011&private=0

/forum/index.php?t=getfile&id=3012&private=0

/forum/index.php?t=getfile&id=3013&private=0

/forum/index.php?t=getfile&id=3014&private=0

Suggestions on what to measure, what to do is most appreciated.

I'm looking for a "local" tech place, hopefully I Can find a good place within next week.

Ben
Re: 8 years later [message #95207 is a reply to message #95199] Sun, 06 February 2022 11:24 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18271
Registered: January 2001
Illuminati (33rd Degree)

I'm so sorry for this trouble! The problem is in the midrange circuit, which uses the components in the center of the board. Specifically, the ones to look at are L2, L3, C4 and R4(a-d) and R5(a-b). Could be a short across C4, but it's had to see in the photos. One way for C4 to get shorted is if something pushes down really hard on L3 causing its leads to come in contact with traces below it. The silicon adhesive is there to support the coil and prevent it from doing that, but it can happen. When that happens, it almost never happens on a fully cured and hardened silicon cushion - which is super-strong - but rather it usually happens while the adhesive is still curing and is still a semi-liquid gel.

For a test, measure across C4. Capacitor C4 is the 20uF part that sits right next to the red coil L4. Without any drivers connected, it should measure 12Ω. But if it's shorted, it will read 0Ω. If that's the case, I would carefully remove coil L3 - the one above the bank of R4 resistors - from the adhesive, leaving its electrical connection intact. If it has shorted into the circuit traces below it, then once you move it so it no longer touches the traces, the midrange circuit will begin to work. If this is the case, I would re-attach the coil with silicon adhesive, being careful not to let the leads touch the traces when positioning the coil. Then let it cure for a week or two without placing weight on it that would press it back onto the PCB traces below it.

When we assemble crossovers, the silicon adhesive curing time is the most lengthy part of the assembly process. It is built-up into a thick cushion which takes a long time to cure. Once cured, it is a very strong silicon rubber pad that can support the coil even if a lot of pressure or weight presses down on the coil. It is very durable. But if we don't allow enough time for the adhesive to cure - if we ship prematurely - then the silicon is still a semi-liquid gel inside. The silicon will film-over and appear to be cured, but it's still "squishy" inside. Weight placed upon it can shift it and sometimes - rarely but I've seen it happen - push the coil's leads down onto the traces below it. So that's what I would look at first.

Again, so sorry this is happening! We test the crossovers before we ship them, and we wait a couple weeks to allow the silicon to cure. But sometimes we find coils that have shifted or lifted and it's always a result of the adhesive not fully curing so that impact loads during shipping make the heavy coils move.
Re: 8 years later [message #95214 is a reply to message #93455] Sun, 06 February 2022 20:11 Go to previous messageGo to next message
panduro is currently offline  panduro
Messages: 32
Registered: March 2013
Location: denmark, european union
Baron
Measuring each lead (not on the pcb track) on C4 it says 12ohm. What should the rest say?

As Long as we get it fixed, its really not a big deal, Shit happens Wayne, win some loose some. I'm totally incapable at this stuff so I expect to resort to finding someone who Can do it for me without shipping it around the world to you.

Ben
Re: 8 years later [message #95217 is a reply to message #95214] Mon, 07 February 2022 10:30 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18271
Registered: January 2001
Illuminati (33rd Degree)

I'm still just so sorry you're having trouble with the crossover. But the 12Ω resistance measured across C4 is exactly right. That tells me the coil didn't get pressed down onto the PCB traces, which is the most common culprit for symptoms like these.
Re: 8 years later [message #95219 is a reply to message #93455] Mon, 07 February 2022 15:52 Go to previous messageGo to next message
panduro is currently offline  panduro
Messages: 32
Registered: March 2013
Location: denmark, european union
Baron
Hey Wayne, I don't in any way doubt that you are sorry that this has happened, I'm also pretty sure that if I asked that you would Pick up at least a part of the shipping cost so you could fix it. But because of the time aspect of shipping back and forth across the world I have chosen to let a local audio tech shop look at the xovers, it is in no way because I am not satisfied in my dealing and service from you.

Is there any info that Can help the tech shop in their quest of my audio satisfaction? I have just handed in the cross overs and schematics... Correct resistance, output voltage or something?

Best regards

Ben
Re: 8 years later [message #95220 is a reply to message #95219] Mon, 07 February 2022 16:44 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18271
Registered: January 2001
Illuminati (33rd Degree)

If you've given them a copy of the plans - with the schematic and PCB layout - they have everything they need.

Please give them my email address and/or direct them to this thread in case they have any other questions. But for an electrical technician, this kind of repair work is as easy as it gets.
Re: 8 years later [message #95225 is a reply to message #93455] Mon, 07 February 2022 19:13 Go to previous messageGo to next message
panduro is currently offline  panduro
Messages: 32
Registered: March 2013
Location: denmark, european union
Baron
Everything is easy when you know what you are doing, just a fact of life lol. At the counter, he also replied that it would be very Strange if they couldn't fix it pretty fast and easy.

They have the 2 pages, pcb and schematic. I Will give them your email if they have further questions.


Ben
Re: 8 years later [message #95226 is a reply to message #95225] Mon, 07 February 2022 20:17 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18271
Registered: January 2001
Illuminati (33rd Degree)

Super groovy cool. Keep us posted. I'm curious to learn what happened.
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