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cabel1975

SW12 Hum....obvious what the problem is, need help to fix

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This happened years ago and I vaguely recall "popping the hood", tightening some connections and all was well until two nights ago.

 

Hopefully the pictures will illustrate, but here's my best description:

 

Relatively loud hum....even if plugged in all by itself to the wall. This unit is a two prong plug FWIW.

 

This time when I popped the hood, I found a ground cable that was just dangling out there....one end is not connected to anything. Pretty sure this is kinda sorta a problem. It is a very short ground wire. The side that is connected is attached to a post on the power-supply/transformer. For the life of me I cannot see where the other end is supposed to be going. I tried screwing it to the overall frame (sounds logical) but that made zero difference in the problem.

 

I also discovered that two of the rubber mounts for the power supply/transformer have split/appear to be broken. These appear mainly to be for isolation so broken rubber sitting on broken rubber shouldn't be a big deal, so I do not think that is my root cause?

 

Help is GREATLY appreciated. LOVE this sub for its quality and also severe sentimental attachment. 

sw1b-IMG_20180831_101629729_LL.jpg

sw2b-IMG_20180831_101629729_LL.jpg

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The ground i would think goes under one of the screw holes when you put the plate back in the box or the bolt rite behind it in the picture so that the transformer has a ground since its on rubber isolaters. The rubber isolaters you can get off of mcmastercar. Just measure there length and bolt size.

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Thank you, Bryan. Took your suggestions, just spent a few hours inspecting all wiring and replaced a few wires that were questionable. Alas, am still in HUM-land. :( 

 

Considering now whether to replace the actual sub-woofer ('speaker') or replace the in-cabinet amp portion of this unit. I think I can steal a sub/speaker from another system and hook it into this one just to test and take this sub/speaker and put it in the other system to at least test out the theory that maybe i can replace one piece or the other.

 

Thanks again, Chris in Denver, CO

Edited by cabel1975

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The hum is from the amp, not the driver.   It's just playing the signal that the amp is sending it.

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Confirmed that the amp is the problem by swapping a known-good speaker into the cabinet (same behavior). Next question then, anyone know where I can purchase just the AMP component? I also truly despise waste, so am reluctant to throw the whole thing out if it can be avoided.

 

Thanks again fellow Klipsch'ers!

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I found this picture at another site. May give you a hint as to where one end of the green wire goes:

 

https://images.crutchfieldonline.com/ImageHandler/trim/620/378/products/2017/37/958/g958MAC7200-F.jpg

 

 

SW12_transformer.JPG.9373902214992b4c6f80bb5fa7e91735.JPGI'll definitely take care of the loose end of the green wire.

 

If you want to repair the amp, the following will be a great help:

 

https://www.audiolabga.com/pdf/SW12-15 I.pdf

 

As to getting parts, I use AliExpress. If you're not in a hurry, their prices are uneatable. If you want parts fast, you could try the following:

 

https://www.newark.com/

 

https://www.mouser.com/

 

 

 

 

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On 9/9/2018 at 6:24 PM, zeron said:

Troubleshooting problem # 4. Just replace the 8 capacitors.

Also pretty sure that lug on end of green wire just goes to the metal panel. Haven't the teeth of the lug dug into the metal of the panel at one of the screw holes? hard to tell from your picture.

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On 9/11/2018 at 2:07 PM, babadono said:

Troubleshooting problem # 4. Just replace the 8 capacitors.

Also pretty sure that lug on end of green wire just goes to the metal panel. Haven't the teeth of the lug dug into the metal of the panel at one of the screw holes? hard to tell from your picture.

Thanks babadono. Will probably take this route in hopes of repair.

 

Also, that was my deduction on the grn/grnd wire also. The "bite marks" aren't seen as I sanded down that area thinking maybe the connection wasn't strong enough, but still in hum-land.

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On 9/9/2018 at 1:07 PM, CECAA850 said:

Look for Edwards Electronics at eBay.   They do repairs.

 

No affil.

CECAA850,

 

Excellent information, THANK YOU! Bookmarking that for future reference.

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10 hours ago, cabel1975 said:

CECAA850,

 

Excellent information, THANK YOU! Bookmarking that for future reference.

Many here have used them here on the forum.  I havent read a negative comment yet.

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