Marantz 2230 restoring it from scratch

I'm not sure about your hum. The way you describe it, it sounds like maybe some kind of oscillation (?). Probably wouldn't hurt to change the big caps, but after that, make sure you go back and get power supply voltage and bias set to spec. If they won't set, that's the next project -- to figure out why.
So when I made the large purchase on Mouser It was recommended to change the 63V 4700uf caps to 80v 6800uf caps. Think it's to much of a change? Should I order a closer replacement?
 
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I don't think those caps will be a problem if they fit. There is another thread going discussing the 2230 coupling and filter caps and how high they can go. I have use 6800uF for the coupling caps and 10000uF for the filter cap without a problem. Opinions are mixed on whether that is a good idea or not, but going from 4700 to 6800 shouldn't be a problem.
 
I don't think those caps will be a problem if they fit. There is another thread going discussing the 2230 coupling and filter caps and how high they can go. I have use 6800uF for the coupling caps and 10000uF for the filter cap without a problem. Opinions are mixed on whether that is a good idea or not, but going from 4700 to 6800 shouldn't be a problem.

We'll just finished those caps..
Makes music, but it still has the annoying low pitch buzz. You can drown it out with volume but that's not a fix.
I've noticed the more you turn on/off the unit, the sound ossolates quickly from high to low pitch when you turn on"Main" speakers. Kinda like the THX intro sound in reverse. .
Here a video of it I made for ya.
 
Wow. That's wild. My experience level is not that great, so I've never heard that before. Surely some of these experienced guys have. I'm still guessing some kind of oscillation, but wouldn't have a clue as to the cause. Does it happen on all inputs?. Do PS voltage and bias set correctly?
 
Looks like you have yoirself a motorboater.

Did it work before all This?

I've never had this issue before but try reading up on subsonic oscillation. This may require a scope to figure out and there are many different things that can cause this but it's not to common on solid state stuff.

Don't hook up any speakers you care about and I wouldnt leave it powered up long.
 
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Wow. That's wild. My experience level is not that great, so I've never heard that before. Surely some of these experienced guys have. I'm still guessing some kind of oscillation, but wouldn't have a clue as to the cause. Does it happen on all inputs?. Do PS voltage and bias set correctly?

I've only tested it on FM. I'll test AUX real quick.
 
Looks like you have yoirself a motorboater.

Did it work before all This?

I've never had this issue before but try reading up on subsonic oscillation. This may require a scope to figure out and there are many different things that can cause this but it's not to common on solid state stuff.

Don't hook up any speakers you care about and I would leave it powered up ling.
So that's kinda why setting bias has been so hard. I set it powered on, but no speakers turned on. Is that ok? Or do you need that load on it?
No scope to play with, but this is the perfect reason to find one
 
You don't need speakers hooked up. Input set to aux, balance at middle and volume at zero. If all is well, bias should set.
 
You don't need speakers hooked up. Input set to aux, balance at middle and volume at zero. If all is well, bias should set.
So I've tested all sources with main speakers on and the hum doesn't even hiccup between switching sources. Stays constant.
As for power voltage. I tried my best to get the voltage down with the new potentiometer. No luck, sits at 40v.
So I'm think ok, bad new part. I'll switch it out for the original. Soldered it in and checked voltage. Still sits at 40v at its lowest turn. But now it can go up to 41.8v....
Could it be the sum of new parts pushes more voltage across the board?
 
I doubt it. Something is wrong on that power board. Look at the schematic and test the voltages where you can. Hopefully you will find some voltages out of spec and get a clue where to look for the problem. Something on that board has to be bad if it won't adjust below 40V.

Question: Did you replace the zener diodes at H806/H807?
 
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I doubt it. Something is wrong on that power board. Look at the schematic and test the voltages where you can. Hopefully you will find some voltages out of spec and get a clue where to look for the problem. Something on that board has to be bad if it won't adjust below 40V.

Question: Did you replace the zener diodes at H806/H807?

I did replace H807 next to capacitor C807.
H806 I don't think so. is it the one with the red arrow? I'm not sure what to use for replacement on that.
H806..PNG
 

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I just wondered if you replaced them because they really have to have the same voltage value as the original. You should be able to check the voltage across each zener with your DC voltmeter. H806 should measure 14V and H807 should measure 7V. I would just make sure the replacement you put in H807 is a proper replacement at 7V.
 
Looks like the correct diode replacement for H806 is NTE144A.
14V 1W vol. tolerance %5.
Mouser doesn't hold them..any sources?
 
I wouldn't replace it unless it doesn't measure around 14V in circuit. I'm more concerned about the one that was replaced to be sure it is at 7V. I am a noob to diagnosis, so I'm kind of shooting in the dark. I normally don't replace zener diodes because they rarely go bad. But since you can't get your voltage to adjust and you replaced most components, I just thought it would be worth checking to be sure your replacement zener is running the proper voltage. Hopefully someone with more diagnostic experience will jump in here and be able to better help you find why you can't get that PS output voltage below 40.
 
Stupid question, but are you playing the unit without the dbt in line. The dbt will cause both hum and motorboating as you increase the draw by turning up the volume. The dbt should only be used to verify the absence of shorts. All adjustments should be made without the dbt. Rich
 
Stupid question, but are you playing the unit without the dbt in line. The dbt will cause both hum and motorboating as you increase the draw by turning up the volume. The dbt should only be used to verify the absence of shorts. All adjustments should be made without the dbt. Rich
I've tried both and the results are the same. that weird buzz

Also, the replacement was correct at 7v.
 
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I just had a hum in my 18 that I could not find, set it to my tech and a cap was in backward. Not bad enough of a problem to blow the cap or light the dbt, but created a partial link to ground and introduced a constant hum that increased when the 'low filter' was pressed. You might just check the error thread to see if the boards a labeled wrong, or if you installed a cap backwards. Rich
 
I just had a hum in my 18 that I could not find, set it to my tech and a cap was in backward. Not bad enough of a problem to blow the cap or light the dbt, but created a partial link to ground and introduced a constant hum that increased when the 'low filter' was pressed. You might just check the error thread to see if the boards a labeled wrong, or if you installed a cap backwards. Rich
Ok, so I replaced the 3.3uf cap on c807. Since the new one is red and labeled as a film capacitor. I figured I could have installed it backwards. Old one in with positive side confirmed. Did not fix it.
I took out the new transistor, on H803 and put back the original. No dice still has hum.

So I turn on the "main" switch and leave it powered on. I heard an audible ticking in sync with the sound I heard from the speakers. Very faint, hard to hear, but I hear it.
It's from this little black box with 4 leads on it and some filter caps to ground.
What is it? Can I replace it? With what?1491153320991603134248.jpg
 
That is a bridge rectifier (H007 on the schematic), it has 4 separate diodes set up to rectify the AC from the transformer secondary winding wiring into "pulsed DC". That is then smoothed out (AKA filtered) by the large rectifier cap. If any of the diodes are open or shorted or breaking down, that will make for hum alright. It can be tested with a meter with the diode function, measuring between the 4 legs in various ways to see the basic health of the 4 diodes inside. That will not point out breakdowns though like watching the output legs "-" and "+". You can set your meter to the AC voltage mode and with minus/black to the chassis and the plus/red lead to the rectifier pack "+" and see if there's voltage showing. There shouldn't be much more than a hundred millivolts or so.

Sorry, I don't have a recommended sub sourced.
 
I'm looking on my phone, so can't be sure, buf I believe that is your bridge rectifier that turns your 120V AC into DC to go to the main filter caps. It's reasonable that your hum could come ftom there. Replacements are available, but I'm not sure what they are. Someone on here will know.
 
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