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Marantz 2220B problem.

Jermy69

Jermy69

Member
I recently started a rebuild of my Marantz 2220B.
While i have experience working with & soldering circuit board, this is my first rebuild on an old receiver.
The only problem I have seems to be a tough one...no one else can figure it out or even give me any useful ideas what it could be.
The problem is on the P700 amplifier board, capacitor C705 (which affects the left channels.)
Upon replacing it with a new cap the left channel sounds...muffled would probably be a good way to describe it. & I can't figure out why.
Yes, the polarity is correct. Yes it's the correct capacitor.
There are only two things I haven't tried...
One is to take it out & reverse the polarity (but it's already correct & I don't know if it would hurt anything.) The second thing would be to get a new capacitor & try it...maybe this one is defective but isn't it extremely rare capacitors are defective????
That channel worked fine before.
Anyone else have any other suggestions or ideas???? I'd really appreciate them
 
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It is very unusual to have muffled sound due to replacing a capacitor with the correct value and correct polarity. First, put back the old one, if the sound is good then check the voltage rating and value of the new capacitor. What other components did you replace in P700?
 
sanjib said:
It is very unusual to have muffled sound due to replacing a capacitor with the correct value and correct polarity. First, put back the old one, if the sound is good then check the voltage rating and value of the new capacitor. What other components did you replace in P700?
Click to expand...

Everything that came in the kit I bought from Irebuildmarantz.com ...everything so far except the relay.
If you're not familiar with the kit, it comes with replacements for all the electrolytic caps on the board, the two diodes at the top of the board (can't remember their position number right off) & a speaker relay. I've done everything except the relay.
 
Jermy69 said:
Everything that came in the kit I bought from Irebuildmarantz.com ...everything so far except the relay.
If you're not familiar with the kit, it comes with replacements for all the electrolytic caps on the board, the two diodes at the top of the board (can't remember their position number right off) & a speaker relay. I've done everything except the relay.
Click to expand...

I should also add just in case I didn't in my original post, the issue didn't start until I replaced that one capacitor.
 
Check the DC voltage at the speaker terminal and adjust it to 0mV by rotating R711 (left channel) and R712 (right channel) and follow SM to set bias
 
Welcome to AK and I hope you get your 2220B working. Pictures always help if you want to take some of that board etc. and post!

I definitely would NOT try this:
Jermy69 said:
One is to take it out & reverse the polarity (but it's already correct & I don't know if it would hurt anything.)
Click to expand...

Did it sound ok before you replaced parts?
Did you only replace C705 and no other work yet?
 
sanjib said:
Check the DC voltage at the speaker terminal and adjust it to 0mV by rotating R711 (left channel) and R712 (right channel) and follow SM to set bias
Click to expand...

I'm not sure how to do that unfortunately.
I know which part you're talking about....just no idea what to do
 
....& no I'm not gonna try to reverse the polarity.
It's already correct.
I put the old capacitor back in & I still have the exact same problem.

As for checking the bias, I have no idea how to do that... In the 2-3 years I've had this receiver, I've fooled around with those out of curiosity but they don't really seem to even do anything & never did.
If these are what you're talking about...
 

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c705 47uf negative side goes to j703 .if it was in backwards it would mess things up .
maybe a wire broke off or something ?
 
The only tools I have (other than soldering kit & the other obvious tools) is a multimeter & I don't even know how to use one really. So yeah I kinda need things dumbed down a little.
 
But again, in the 2-3 years I've had this receiver I've messed with these white "knobs" (if you wanna call em that) several times & they never seemed to do anything. But I haven't touched them in a while...quite a while actually, & didn't bother them when putting the new caps & diodes in.
Literally everything was ok until I changed out that one C705 capacitor. Everything was ok until I did that one.
 

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