2216 filter cap replacement

[tarior]

You can get the proper part from Allied, probably $7 or $8, shipped. They're PDQ on shipping, and I'm pretty sure they don't have a minimum order. Same story with Mouser, maybe another buck more.
The resistor in series with cap is kinda hokey, and adds leads and a solder joint that would need to be insulated. Do it right.

 

[Tucker99]

Tarior ....no problem with the 'do it right' philosophy!

Everyone ...

Status up-date..... I have re-capped the amp board and tried switching in and out the noise suppression cap across the switch. The result .... no change whatever in the on/off noise.

I then further cleaned and worked the power switch itself (I had done it right at the beginning but this time I did it, like, a lot !) and believe that it is as well cleaned and lubed as it can be done from the outside (i.e. without taking the switch apart). Result ... a very much smoother switching and a significant reduction in the on/off switching noise.

But now I am having an additional problem(s) .... these are they symptoms I am now seeing ....

a) with the receiver in 'aux' mode but no input attached I have a 'hum' that increases as the volume increases,

b) this hum diminishes when I touch the metal chassis anywhere including the volume control shaft, and

c) with the unit switched 'off' if I move the speaker selector switch from 'none' to 'main' to 'remote' to 'both' with only speakers connected to 'main' I get a contact noise through the speakers when I hit the 'main' and 'both' ....like there is a signal even with the unit switched off.

I have rechecked all the caps and polarity looks fine. Same for the new solder joints.

Is it possible (or am I grasping at straws) that the cleaner-lubricant that I used to clean the power switch ["Nu-Trol Control Cleaner", 'with Special Lubricating Oils' by MG Chemicals) has left sufficient lubricants in the switch that it is actually conducting through the switch, or something? I did give it a really heavy dose....

Whatever have I done now ? ! ? !

Ideas please?

PS... This is my first effort inside a receiver and I know my learning curve is steep ...so please bear with me !

 

[secondslc]

Tarior ....no problem with the 'do it right' philosophy!

Everyone ...

Status up-date..... I have re-capped the amp board and tried switching in and out the noise suppression cap across the switch. The result .... no change whatever in the on/off noise.

I then further cleaned and worked the power switch itself (I had done it right at the beginning but this time I did it, like, a lot !) and believe that it is as well cleaned and lubed as it can be done from the outside (i.e. without taking the switch apart). Result ... a very much smoother switching and a significant reduction in the on/off switching noise.

But now I am having an additional problem(s) .... these are they symptoms I am now seeing ....

a) with the receiver in 'aux' mode but no input attached I have a 'hum' that increases as the volume increases,

b) this hum diminishes when I touch the metal chassis anywhere including the volume control shaft, and

c) with the unit switched 'off' if I move the speaker selector switch from 'none' to 'main' to 'remote' to 'both' with only speakers connected to 'main' I get a contact noise through the speakers when I hit the 'main' and 'both' ....like there is a signal even with the unit switched off.

I have rechecked all the caps and polarity looks fine. Same for the new solder joints.

Is it possible (or am I grasping at straws) that the cleaner-lubricant that I used to clean the power switch ["Nu-Trol Control Cleaner", 'with Special Lubricating Oils' by MG Chemicals) has left sufficient lubricants in the switch that it is actually conducting through the switch, or something? I did give it a really heavy dose....

Whatever have I done now ? ! ? !

Ideas please?

PS... This is my first effort inside a receiver and I know my learning curve is steep ...so please bear with me !

(a&b) check your grounds, check for cold solder joints. Can you describe the frequency of the hum?

(c) does it do it a long time after the unit has shut down? You could be releasing capacitance stored in the unit by moving that switch. Remember, the caps are directly coupled to the output, the energy stays unless something dissipates it (speakers). Try doing that a few times and see if it gets less prominent. If it eventually goes away by doing that, leave the unit for a little while, and move the same switch again, shouldn't be any noise.

Its good to hear the power switch cleaning helped, I have never cleaned a marantz power switch as I hear the lube ruins them, i cant explain it, but someone (tom?) may be able to. Maybe clean the switch with a NON lubricating cleaner and see if things go away.

 

[Oerets]

If you suspect that the spray used is causing problems , spray it down with some zero residue cleaner and let dry .
The hum sounds like a grounding problem to me also . Check to see if a RCA connection on the back panel has lost it's ground ?



Barney

 

[Tucker99]

Progress !

I went and got some 'zero residue' cleaner and that solved the switch problem. Now I am uncertain if I was the one who created the problem in the first place, possibly by using a less than ideal cleaner on a power switch and then compounding the initial 'noise on switch on/off' problem by thinking that 'some was good...more must be better'. Cleaning the switch with zero residue cleaner has solved the noise through the power switch and the conductive and grounding type noise... at least most of it.

Left I have:

a) on 'aux' (with no load, i.e. no CD player etc plugged into the receiver) some higher pitched 'hum' when I turn the volume past about 2 o'clock (which I admit is higher than one would use this receiver.

b) same for 'phono' but the 'hum' is a very much lower tone.

I have just tried the 'am' radio and it sounds fine....no noticeable noise.

I have to run a brief errand but next I want to try the 'AUX' with a CD player and see how it sounds.

I am wondering if I should clean all of the controls with the zero-residue cleaner now that I know that the cleaner with a residual lubricant seems to have some 'conductive qualities'..... any thoughts before I proceed ?

 

[secondslc]

Progress !


Left I have:

a) on 'aux' (with no load, i.e. no CD player etc plugged into the receiver) some higher pitched 'hum' when I turn the volume past about 2 o'clock (which I admit is higher than one would use this receiver.

b) same for 'phono' but the 'hum' is a very much lower tone.

I have just tried the 'am' radio and it sounds fine....no noticeable noise.

I have to run a brief errand but next I want to try the 'AUX' with a CD player and see how it sounds.

I am wondering if I should clean all of the controls with the zero-residue cleaner now that I know that the cleaner with a residual lubricant seems to have some 'conductive qualities'..... any thoughts before I proceed ?

Glad to hear the noise went away!

I dont think you will 100% eliminate the noise in the path unless you went and replaced any leaky transistors/diodes/resistors with newer, higher spec ones.

The other switches and pots are ok with the proper lube, if what you used is like faderlube, then sit back and enjoy after finishing the re-cap of course

 

[Tucker99]

The hum sounds like a grounding problem to me also . Check to see if a RCA connection on the back panel has lost it's ground ?

OK....I suspect that I am leading into a dumb question.....

I have now re-capped all boards (power, amp, phono & tone) except the radio.

I still have the 'hum problem. that is, the 'hum' problem definitely was not in the caps....

Symptomatically, here is what I am seeing with no load on either the phono or aux inputs but with speakers connected: a) a 'hum' that increases with volume, i.e. very low hum at very low volume, louder hum at higher volume, b) the hum increases with increased treble and with increased base, c) with the volume up over, say about 1 o'clock, when I touch the chassis I can hear a change in the noise through the speakers, and d) the hum is louder when 'phono' is selected than it is when 'aus' is selected.

I have visually checked the grounds (i.e. all the grounding screws that are attached to the chassis) and all 'looks' OK ....

Now for the dumb part .... what more ought I try or do .... or is it 'tech time'?

I know that handing it over to a tech means 'more money than its worth' in actual $$$ terms but it is a nice unit otherwise and I am kinda (well, maybe not just kinda!) stubborn enough to do that if necessary!

I should add that in terms of equipment I am armed with a basic multi-meter ... but I guess that its not automatic because when I lay it beside the receiver, well, it just lays there!

Anyhow, all final words of wisdom are welcome.... and thanks again for all contributions to date ....

 

[secondslc]

OK....I suspect that I am leading into a dumb question.....

I have now re-capped all boards (power, amp, phono & tone) except the radio.

I still have the 'hum problem. that is, the 'hum' problem definitely was not in the caps....

Symptomatically, here is what I am seeing with no load on either the phono or aux inputs but with speakers connected: a) a 'hum' that increases with volume, i.e. very low hum at very low volume, louder hum at higher volume, b) the hum increases with increased treble and with increased base, c) with the volume up over, say about 1 o'clock, when I touch the chassis I can hear a change in the noise through the speakers, and d) the hum is louder when 'phono' is selected than it is when 'aus' is selected.

I have visually checked the grounds (i.e. all the grounding screws that are attached to the chassis) and all 'looks' OK ....

Now for the dumb part .... what more ought I try or do .... or is it 'tech time'?

I know that handing it over to a tech means 'more money than its worth' in actual $$$ terms but it is a nice unit otherwise and I am kinda (well, maybe not just kinda!) stubborn enough to do that if necessary!

I should add that in terms of equipment I am armed with a basic multi-meter ... but I guess that its not automatic because when I lay it beside the receiver, well, it just lays there!

Anyhow, all final words of wisdom are welcome.... and thanks again for all contributions to date ....

Does the hum change when you touch any part of the chassis? Can you touch any NOT HIGH VOLTAGE components in the unit to hush the hum? If so, you have a bad ground.

Check your solder joints, your wire wrap points. Everything.

Is the hum the same frequency at every volume level?

Its not tech time, its you time, and we are all the "techs" you may need.

We wont give up!:yes:

 

[Tucker99]

Secondslc...

Thanks for the quick reply...and the encouragement !

It seems that is definitely a ground problem, my humble opinion.... yes, the hum changes when I touch the chassis ... seems a bit more pronounced when I touch the unit. CORRECTION ...you are right....it diminishes when I touch things!

Checking solder joints .... can you describe what I should be looking for ? If it is a ground problem, might it be my new solder joints ?

Wire wrap points ...again, am I looking to see if anything is touching that perhaps ought not ?

One symptom has changed tho, and that is in the noise through the 'aux' channel.... I, again, cleaned the volume pot with the zero residue cleaner. I also re-flowed what looked like a loose solder point (yes, one of mine!) on the amp board. Not sure which solved that issue. But I guess that it could be the solder job ? ? I did not really think the kind of symptom I am experiencing through the phono channel would be a cap solder point problem ...but am I wrong on that???

Why would the hum now only seem to be through the phono channel?

 

[secondslc]

Secondslc...

Thanks for the quick reply...and the encouragement !

It seems that is definitely a ground problem, my humble opinion.... yes, the hum changes when I touch the chassis ... seems a bit more pronounced when I touch the unit.

Checking solder joints .... can you describe what I should be looking for ? If it is a ground problem, might it be my new solder joints ?

Wire wrap points ...again, am I looking to see if anything is touching that perhaps ought not ?

One symptom has changed tho, and that is in the noise through the 'aux' channel.... I, again, cleaned the volume pot with the zero residue cleaner. I also re-flowed what looked like a loose solder point (yes, one of mine!) on the amp board. Not sure which solved that issue. But I guess that it could be the solder job ? ? I did not really think the kind of symptom I am experiencing through the phono channel would be a cap solder point problem ...but am I wrong on that???

Why would the hum now only seem to be through the phono channel?

Inspect the solder joint, and if you see any rings on them, or they dont look all that smooth then it may be a problem. If they are dull, then they could be problematic.

What kind of soldering iron do you have? If possible, maybe go through the unit and touch each solder point till it melts. That will eliminate any damaged joints.

These were cold solder joints on my PM-94. I removed the old solder and re-did them all to make sure I didn't miss anything. Unit works with NO issues now.

After....