MARANTZ 2230 LOW FILTER SWITCH CAUSING LOUD POP

[PROJECT 2501]

Engaging/disengaging Low Filter switch causes loud popping noise through the speakers. Regardless of the position of the volume dial the popping noise is audible and unaffected by attenuation. I have verified that this is an isolated issue with the low filter switch and only the low filter switch.
Would this indicate failing capacitors on the preamp tone board? Does the manipulation of the low filter switch discharge DC from the capacitor which momentarily finds way through my speakers?
To my dismay, I would imagine that the issue is unlikely caused by a dirty switch and the solution to my predicament will require attention of which a $15 bottle of stereo sauce is incapable of providing.
Please advise.

 

[patfont]

Hit it with some Deoxit, "it is" likely the problem.

 

[rBuckner]

I'm with Pat (as usual) that a noisy switch is the issue. The caps involved in the low filter circuit are on the filter board, not the tone control and are .047uF. That won't pack much of a pop!

 

[jblmar]

Agreed with the above. Try Deoxit first on the switch.

 

[PROJECT 2501]

Thanks for the advice guys

 

[johndoe10]

Greetings,

Did you ever resolve the popping issue from the Low Filter switch? What was the actual cause?

Thanks,

Jim

 

[patfont]

I am sure the deoxit fixed the problem

 

[johndoe10]

Doubt it

 

[johndoe10]

I have a Pioneer SX-727 receiver with the same issue, Deoxit has not and will not remedy this issue.

 

[patfont]

Hey Jim, I thought you had a 2230, and most times that is the fix. Since you are now saying you have a 727, I would guess it is one of the bad blue Sanyo caps. You may want to post in the Pioneer forum?

 

[johndoe10]

I do have a post on that forum as well, I just ran across this one accidently and figured I'd inquire, but hey, thanks for the advice. I will change the blue Sanyo caps as you directed....Hope that remedies the problem.

Thanks again,

Jim

 

[johndoe10]

Thanks everyone for your very helpful advice, replacing the blue Sanyo caps remedied the noisy switch issue.

Thanks again,

Jim

 

[patfont]

Nice! Glad that did it.

 

[KutzlerTrans]

Good call Mr Pat

 

[rBuckner]

Pat... I am the original owner of a Pioneer SX-626. The only two parts replaced besides bulbs? Those Sanyo caps!!

 

[patfont]

[Q UOTE="rBuckner, post: 9681704, member: 68225"]Pat... I am the original owner of a Pioneer SX-626. The only two parts replaced besides

bulbs? Those Sanyo caps!![/QUOTE]

The 626 is a cap coupled beast, I use one in my testing area, still ticking!

 

[PROJECT 2501]

De-oxit did not fix the problem...
I believe capacitor C754 has gone open. I have a loud channel....preamp is steady but left power amp is on the fritz.....
The 2230 is still used in my main rig though...
I have it controlling a model 32 and it's performing well as a dedicated preamp...

 

[PROJECT 2501]

 

[PROJECT 2501]

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