• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

2216 non-B Strangeness

grey_beard

grey_beard

Active Member
Background:
I picked up my first Marantz receiver yesterday, a 2216 in good physical condition but with some obvious issues. I spent 6+ hours reading and troubleshooting. I could really use some help at this point. I am a novice, but I am ready to take the plunge and I feel this receiver is as good a place as any to get started.

Issue #1:
All front panel lamps are blown with the exception of the tuner dial indicator. I am hoping that this is just from years of neglect and not the result of a catastrophic issue. I am planning on simply replacing the lamps.

Issue #2:
Crackly sounding pots. Easy fix. Deoxit and it sounds clean and clear. They should all be this easy.

Issue #3:
Here's the reason for this thread. Right channel distortion at all volume levels on all input sources anytime there is a speaker connected to the right channel of either output 1 or 2 and the speaker selector is sending load to that output. There is NO distortion through headphones as long as the speaker selector switch is turned "Off" or there is no speaker connected to the right channel of the selected output. As soon as a speaker is activated on the right channel the headphones right channel becomes distorted as well. There is also no distortion when feeding audio through Tape Out regardless of speakers being connected and speaker selector switch being activated.

I have the schematic and a serviceable multimeter and a desire to learn how to solder...

With that said, I am a novice so please be gentle.

Thank you in advance,
grey_beard
 
Register to hide this ad
Try getting some Deoxit into the speaker selector switch . Then click it on and off about 30 times . You might luck out with just a dirty switch . There is a fuse that powers the Lamps . Look for 3 fuses next to each other on a fuse board . It should be inside the unit . Maybe located on the bottom of the chassis . I am not referring to the one 120 Volt line fuse on the back of unit . Check to make sure one or all three are not blown . Good luck with your new project .
 
I did clean the pots and switches which helped some issues. The distortion on the right channel is different. It sounds overdriven but quieter than the left channel. Also, it is present on System 1, System 2, and through headphones anytime there is a speaker connected to the right channel. Tape Out is pristine.
 
catrafter said:
It appears to me that you have a problem in the right channel power amp, it will drive the light load of headphones, but not the heavier load of a speaker.

Tom
Click to expand...
Thank you for your reply, Tom. I believe you are correct. The fact that the Tape Out exhibits a clean audio signal I believe also points to the Right Channel of the Power Amp section having the issue.

I'm a super NOOB at troubleshooting this stuff. I can read and follow the schematic and I have a basic digital multimeter I can use to test for resistance and capacitance.

Would anyone be willing to suggest a next-step for testing to begin to further isolate the issue? I would be greatly appreciative.

Also, I am contemplating getting a handheld scope. Any advice???

Thank you to everyone who has chimed in and those who have taken the time to read.

Gary
 
The nice thing about having one channel working correctly is that you can compare voltages/signal at various points between the good and bad amp board channels which will give you a decent starting off point once you're armed with a schematic.

Bob
 
Update:
I recapped the right side of the main amp board and replaced the light bulb on the right side of the amp board. I also replaced the output transistors. The result... no improvement.

For some reason the variable resistor used to adjust bias on the right side doesn't affect the bias voltage.

I checked voltage at the jumpers on the amp board. Here are the results with no load. I'm guessing I need to put in a test tone which I'll do and report back asap.

J701 0.3 VDC
J702 0.2 VDC
J703 0.0 VDC
J704 -0.1 VDC
J705 -0.1 VDC
J706 55.3 VDC
J707 -0.3 VDC

If anyone has any pointers at this point I would appreciate it. I have a DMM but no scope.

Thanks in advance.
 
I put a test tone through aux and found a strangeness at J705. It measures 10% of what J704 measures. In this case J704 was 0.213 VAC and J705 was 0.026 VAC. Looking at the schematic, this just confirms what I am hearing from the speakers.

Now to figure out why...
 
I pulled and checked all the transistors on the amp board and all appear fine. I also checked the variable resistor used to set bias and it too appears to be intact.

Next I think I will pull the newly replaced output transistors and see if they were damaged after putting them in. Seems unlikely since I just put them in last night.

Any one have any advice at this point?
 
Good news. It looks like its working now. Replaced all four of the 22ohm 3 watt resistors and the re-blown output transistors seems to have cured it.

Now I have a different issue. With the variable resistors cranked all the way down, the lowest bias reading I can get is 28mV - way too high. Recommended is 4.5mV.

Has anyone else seen this?

For some reason there is too much voltage leaking through to the resistors with the volume all way down and no load.

Any help would be great.

Gary
 
Is it ill advised to replace this with .33 ohm 3 watt resistor?

The only reason I ask is because I can't find the .22 ohm locally.

Thanks.
 

Attachments

  • point22ohmresistor.JPG
    point22ohmresistor.JPG
    49.7 KB · Views: 6
grey_beard said:
Is it ill advised to replace this with .33 ohm 3 watt resistor?

The only reason I ask is because I can't find the .22 ohm locally.

Thanks.
Click to expand...
You would need to recalculate the bias setting. If using .33Ω you would need to shoot for 6.7mv rather than 4.5mv.
 
Last edited:
Thanks, avionic. I ended up ordering from Digikey rather than getting the .33ohm locally. Better to just get the right part.

I have a 2226b to open up this weekend so that'll give me something to keep busy with.
:cool:
 
Thank you to avionic, Beamer32, catrafter, and wlhd1610 for your help on this thread.

This has been a great learning experience and served to greatly improve my soldering skills.

In the end I recapped both channels of the main amp board as well as replacing the output transistors and the resistors leading to the outputs. I also replaced the burned out lights with new LEDs. Bias adjustment was super easy on this amp and everything was nice and accessible. I would highly recommend this piece for a good starter project.

And now this 2216 is making beautiful music. I'll probably hang on to it for a while before passing it on as it just sounds so nice. This is my first Marantz and I can certainly hear what all the hubbub is about. Beautiful sound stage. Clear and glorious phono stage. Miles and Coltrane sound amazing.

Thank you again to everyone for your tips and gracious patience as I muddled through this.

Be well,
Gary
 
You must log in or register to reply here.
Back
Top Bottom