5.1 Ultra - Loud Humming - Control pod or amp?

[Yura]

Although this is an old topic - it helped me a lot and I want to thank everyone who contributed. My Ultra 5.1 are going strong and now sound clean again with no hum.

[mmclam]

I read with interest the post by StPete Cooling re repairing a buzz coming from Klipsch ProMedia 2.1 BT Speakers. 

 

I bought a ProMedia on 12/4/16 and used it for only a few months before my schedule changed. In March, I unplugged the subwoofer and custom desktop and they both sat, unused, for 1.5 years. (Nobody uses my office equipment.)

 

After replacing our wired home phone with a VOIP phone system recently, we found the subwoofer interfered with VOIP operation even if it wasn't plugged in. Called party hears nothing when we place calls ... no voice, no static, no beeps, no hum, no buzz. Today, we plugged in the subwoofer in an attempt to move equipment around to solve phone problem. For the first time, we heard constant static. This infuriated me since the ProMedia had only been used maybe 5-10 hrs per week for 3 months. And whenever a new window displayed on the screen, there was static over static. I moved the speakers around, checked connections and organized the wires. No change.

 

I kept moving stuff on top and below my desk. Voila! The static turned into a buzz. That's improvement! I switched the speakers and moved wires around, but the buzz continued. But when the speaker was lying flat in my hand, the buzz became softer. I kept turning the speaker around in all directions for, maybe,  20 seconds and, all of a sudden, the buzz disappeared. Totally. The noise wasn't made worse or better by turning the volume knob. All I know is that I don't have to bring the system into a local shop that repairs premium equipment like Thiel or restores vintage pieces like Tandberg. 

 

Next time, I'll pick speakers with no sub given the issues with Klipsch equipment noted here. StPete Cooling: I've kept your instructions and this URL in case my repair shop needs them later! 

Edited October 20, 2018 by mmclam
spelling errors

[cmay7725]

I know this thread has been brought back from the dead quite a bit, but does anyone have an idea on why the center channel would have a dissipation or discharge sound when the pro media's power off? Audio comes out from the center channel fine it seems at the moment, but the volume does "seem" lower, I suspect this is a precursor to failure. I've already replaced the two caps for the hum and that's been gone for a while now (thanks Stpete Cooling!).

 

 

Edited December 29, 2018 by cmay7725

[Need4Speed]

On 5/14/2010 at 4:27 PM, stpete cooling said:

The hum is almost certainly from one of two 100mFd 35 volt capacitors on the main board next to a pair of small, black heat sinks. You have to be careful removing the old capacitor that you don't damage the leads--they are a bit difficult to access with a soldering pencil. I always replace these as part of every repair--the hum is so common on older panels. I recommend using 105 degree Celsius capacitors, in place of the original 85 degree rating. I also bend into a "Z" (offset) the lead that will be closer to the heat sink so that the capacitor is mounted as far from the heat sink as possible.

The control boxes on eBay vary widely in price. One sold for $82 plus shipping this week; another sold for $24 something and shipping.

 

Another win!  Thanks for this ancient thread.  My ProMedia 5.1 recently started buzzing loudly through the subwoofer, and I thought it was toast.

I first replaced the two easier capacitors on the power supply board that others have replaced.  No dice.

 

Then I moved on to the two mentioned by stpete cooling.  After carefully replacing them and plugging the unit in, sweet silence!  (Well, sweet until I connect my speakers back up and run some music through it!)

 

Thanks!

[Need4Speed]

On 5/25/2020 at 3:44 PM, Need4Speed said:

 

Another win!  Thanks for this ancient thread.  My ProMedia 5.1 recently started buzzing loudly through the subwoofer, and I thought it was toast.

I first replaced the two easier capacitors on the power supply board that others have replaced.  No dice.

 

Then I moved on to the two mentioned by stpete cooling.  After carefully replacing them and plugging the unit in, sweet silence!  (Well, sweet until I connect my speakers back up and run some music through it!)

 

Thanks!

 

Update: after hooking things back up, the sound is back and is beautiful!

 

Edited May 27, 2020 by Need4Speed

[ironmike]

stpete's suggestion worked for me on my Ultras here in 2021. Can't believe these things still work! As suggested, it's capacitors C35/36. I was in a bit of a rush before heading out of town and was able to get these capacitors off Amazon delivered the next day - https://www.amazon.com/gp/product/B07Y3F194W/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

[Proddie]

I have Pro Media 5.1's I bought December 2020, they just started buzzing loudly through the speakers (less than 6 months). I pulled out the control board and don't see any damage... I ordered the capacitors from the link above thinking those should work before I looked at the board, but there is no matching capacitors on the board. Not going to keep ordering capacitors and trying to replace... Guess I will see if I can return it to Costco. Definitely not ever getting a Klipsch product again.

[Xytal]

I made an account to come here and say thank you to stpete cooling for indicating the problem, TopMarc & novinha for helping out exactly where the capacitors are and tips on what to do (never soldered before), and ironmike for the Amazon link to the capacitors.

 

Took me probably 30-45 minutes to do, and my 5.1 Ultra's are now working perfectly again, no BUZZING!

 

Totally worth the burn I got on my left index finger and thumb (it was after I was done and cleaning up, I was stupid, don't ask 😶) doing this.

 

Thank you all so much!

[Astroman]

Hi,

There is no way I’ll be able to make that simple fix on my own with my Pro Media 5.1 ultra’s. My humming started about 6 months ago. Is there anyone doing this repair without charging an arm and a leg? Stpete are you still repairing these? Thanks in advance.

[pman62]

my promedia v2 400 also got this nasty buzzing and hissing recently, after 23 years of use.

two bad 47uf capacitors that both lost 80% capacitance, replaced with panasonic 105c caps.

They use the cheapest caps in these amps.

[Cliffee]

Hi Everyone,

 

Want to thank those who provided the information on the cause and fix for the horrid hum that results of the two 100mfd caps cause when they go bad.

A few weeks ago I started experiencing a loud hum in both 5.1 speakers and using head phones jack.

The hum would slowly go away as the amp warmed up but never completely. Eventually the hum got much louder at cold startup and didn't go away.

I replaced the two caps as instructed here and its now whisper silent! Its so silent, when I first turned it on I thought I messed something up and is was dead. LOL

Not only that but I can hear more detail in voices and the sound is overall clearer than before.

 

Thank you so much!

 

-BR

Cliff

[StaticCrowbar]

Nearly 13 years later, and this is still valuable information! Thought for sure these speakers were garbage-bound (these are the second set I owned, the first got tossed back in 2008 for the same issue because I didn't know how to fix the), but the advice here saved my gear! The 35v 100mF caps at spots 35 and 36 were indeed bad. Ordered new ones from McMaster-Carr yesterday and just finished installing them ten minutes ago! Thank you to everyone for their info here!!!

[klipschaddict]

just wanted to give a big thank you to stpete cooling for the info. i grabbed 2 nichicon UEP1V101MPD caps from digikey and installed them this afternoon. like someone else said, i thought i wasn't successful at first because there was absolutely NO noise coming from the speakers when i hooked them back up LOL. they sound as good as the day i bought them now!!!

 

i actually created this account JUST to thank you. 😁

Edited April 20 by klipschaddict