Buzzing sound from power conditioner

jean-paul

diyAudio Moderator Emeritus
2002-09-20 7:20 am
Germany
The one that is now in it probably causing the trouble!

Now there are only a handful of electrolytic caps in that device so replacing that handful when of suspected quality is looking forward. BTW did you the the error in post #15 in my device? Give and take, mr. Wilson.
 
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jean-paul

diyAudio Moderator Emeritus
2002-09-20 7:20 am
Germany
Mmmm difficult for anglosaxon people. Just suppose that 47 µF is kaputt. First thing to check is value and what brand it is but no reply (important parameter). Now if that cap is crappy ultra low cost quality and the others are too then maybe it is a good idea to replace them all for known good caps. Not "least effort/cheap" but quality/longevity.

Slogan:"open once, enjoy longer" or the like. OOEL yeah!
 
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What he means is change all the diodes in the bridge with good quality parts.
And all the electrolytic caps in the entire unit, with good Japanese or European capacitors. 105 degree long life unit types intended for this kind of use.

Panasonic, Elna, Nichicon, Nippon Con-Chemie, Rubycon, Taicon (Taiwan), Wilma. Sprague, Vishay...all are reputed.

Also, this is a tap changer type unit, with triacs doing the switching?
It tries to control the input or output to give a steady output voltage?

Then please post photos of those, and the nameplate of the unit.
That part may also need modification.
 
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mwilson

Member
2021-09-13 3:44 pm
Correct. Do it good straight away or don't do it at all.

Alas, I am but a novice so please go easy on me. I will follow all the good advice I've received in this thread, for which I am very grateful, but replacing all at once seems like a big challenge for me. I'm comfortable changing a thing here and there as long as it fixes the problem, but to completely replace components is above my level.

BTW, I tried finding someone local to come and perform this for me, but wasn't successful—I'd gladly pay someone if I could. And unfortunately, due to recent surgery, I cannot lift this unit and take it to a repair shop (it weighs 90lbs, about 40kg or so).
 

jean-paul

diyAudio Moderator Emeritus
2002-09-20 7:20 am
Germany
Aha OK. Then the diodes and a Pana cap. Work with desoldering braid or a pump and as short as possible. If there is someone near you with skills then ask assistance. Don’t make the mistake to solder the diodes or the cap in the wrong direction.

If you remove the small PCB anyone slightly electrical gifted can do it perfectly. If you want it done you can send it to me even. Just the PCB….In any case make pictures before for correct assembly.
 
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mwilson

Member
2021-09-13 3:44 pm
I know I've written this before, but once again I really, really appreciate all the help that's been provided to me.

As a side note, reason I've posted on diyaudio is because I've been reading a lot about amps here, especially in the Pass Labs section, and I found it all very educational, even though I'm quite the novice. The engagement level of the community encouraged me to register and start this thread.
 

mwilson

Member
2021-09-13 3:44 pm
Update. I'm back home, and took the pcb out of the unit for testing.

The capacitor is Jamicon, and removed from the pcb measures at 44uF. Diodes are all ok.

I connected 120V and neutral via alligator clamps, relay switches and is dead silent. Zero noise. I placed the pcb back into the Furman, turned on, buzz is present. Turned off, I then disconnected then output of the relay, zero noise. Reconnected the load, buzzing back on. It appears that is it, so unsure where to go from here. Pcb and relay on their own are perfectly fine. The relay connects 120V to that large capacitor you can see in the first photo in my original post.

So I took a decidedly mechanical approach here, simply surrounded that pcb with sponge-like shipping protectors to diffuse/absorb the sound emitted, while still leaving some room for ventilation. I no longer hear the buzzing sound. Not happy with the solution but for now it will have to do.