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Marantz 2220b Dead right channel

Without a high res schematic for the 2220B, that includes the voltages, it's tough to determine what to be expecting at which transistor. I would pull the 945's first because of their reputation for failure, and test them out of the circuit.

What would be the correct, or proper method for troubleshooting this problem?
 
MarantzRefrb said:
Without a high res schematic for the 2220B, that includes the voltages, it's tough to determine what to be expecting at which transistor. I would pull the 945's first because of their reputation for failure, and test them out of the circuit.

What would be the correct, or proper method for troubleshooting this problem?
Click to expand...

Ok, thank you. Would you know the values of these 4 transistors out of the circuit? Thanks!!
 
If you have a tester such as a DC55 or DCA75, it will give you the specifics of a particular transistor:
E817Bfb.jpg


agQ6rbr.jpg


These testers will give you the hfe, or gain value too, which is the numbers you sometimes will need to match to other transistors. The really nice thing about these testers, is they tell you exactly which leg is Emitter, Base, or Collector - this is very helpful when replacing with subs, where the pin out is different.
 
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The main thing you are looking for when testing transistors is conduction in one direction of each pair of leads (B-C, B-E, C-E) and no conduction in another direction. Transistors either fail short - current passes when it shouldn’t, or open - current doesn’t pass when it should. The transistor testers make it easy, but you can test for open or short with the diode test function of a DMM. Here is a step by step guide to that process. It seems cumbersome at first. But once you get it, you can test a transistor in seconds.
https://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/
 
Steven Tate said:
The main thing you are looking for when testing transistors is conduction in one direction of each pair of leads (B-C, B-E, C-E) and no conduction in another direction. Transistors either fail short - current passes when it shouldn’t, or open - current doesn’t pass when it should. The transistor testers make it easy, but you can test for open or short with the diode test function of a DMM. Here is a step by step guide to that process. It seems cumbersome at first. But once you get it, you can test a transistor in seconds.
https://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/
Click to expand...

Pulled the 945's last night. I used my DMM to test them using the method here. All 4 tested at .65. I have ordered 4 new ones to replace when I do my recap. One thing I did run across last night was while I had the unit on and I was getting audio from the left, I tapped on the relay and got some static audio out of the right channel. This hadn't happened up until this point. Thinking I could pull off the plastic shroud and deox that piece?? Any thoughts?

Thank you for all of your help so far!!

Jason
 
Hello,

I'm curious which 2220B relay you have. the clear one or the hazy translucent one.

This might help:
https://audiokarma.org/forums/index...eaker-relay-replacement.881545/#post-13024340

Also, "There were 2 different relays used during the production life of the 2220B. The clear covered one is comparable to a modern MY series from Omron. The hazy, translucent one doesn’t have a modern comparable."

More discussion of the issue here:
https://audiokarma.org/forums/index.php?threads/need-a-relay-for-my-2220b-not-an-my.418602/
 
fromnowon said:
Hello,

fromnowon said:
Hello,

I'm curious which 2220B relay you have. the clear one or the hazy translucent one.

I've attached a picture, I think it's the hazy translucent version. I do have one in order with the rest of the parts I need to rebuild this board.

One item I couldn't find was the two transistors that screw into the back of the heat sink. I've attached a pic of those also.

Thanks for the help!
20201201_203423.jpg 20201201_203511.jpg
Stay safe!
Click to expand...
Click to expand...
 
MarantzRefrb said:
Good work on testing the transistors. It sounds like you are on to something there, with tapping the relay and getting sound. The relay is cheap, and worth replacing.

I think this is the one you need, hopefully someone will confirm this:
https://www.mouser.com/ProductDetail/omron/my2-02-ac110-120/?qs=NHN4o8quFyQHBzu7e%2bbWUw==
Click to expand...
Good work on testing the transistors. It sounds like you are on to something there, with tapping the relay and getting sound. The relay is cheap, and worth replacing.

Thank you! Seemed to be fairly straight forward. You're the third person to sell me on that component tester. Looks like that'll be on my Christmas list this year!
 
goodshelac said:
I've attached a picture, I think it's the hazy translucent version. I do have one in order with the rest of the parts I need to rebuild this board.

One item I couldn't find was the two transistors that screw into the back of the heat sink. I've attached a pic of those also.

Thanks for the help!
index.php



index.php

Stay safe!
Click to expand...

:thumbsup:
 
fromnowon said:
That looks like the LC relay, the translucent one, that does not have a direct replacement.
So you might have to do some engineering?
I had a plan at one time to chassis mount a new relay and solder wires - haven't had a chance to get to it:
https://audiokarma.org/forums/index...eaker-relay-replacement.881545/#post-13024340
I'm planning to try a MY2-02-DC24 in my 2220B.
Which relay did you order?
Click to expand...
This is the relay that I ordered. It is part of a rebuild kit that comes with other caps, diodes, and transistors.
 

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Interesting. Will you please post back with how it works and fits?

Actually the one I was planning to try (with stand-offs and wires) is MY2F-DC24
 
fromnowon said:
Interesting. Will you please post back with how it works and fits?

Actually the one I was planning to try (with stand-offs and wires) is MY2F-DC24
Click to expand...

I will post updates as I start to replace the parts. I'm still learning how to work on these so it may take me a little bit. I'm also not the greatest on terminology so I'm still a little lost about your part
MY2F-DC24. I'm not sure what that means, thank the Lord for AK!

Do you know where I may get the transistors that I posted yesterday? The ones marked with the number 58 and are screw mounted to the back of the heat sink?
 

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Also was going to mention this alternative inexpensive transistor tester. Seems to work pretty well for identifying leads on transistors to make sure they are correct.

Capture2.JPG
 
Sorry one more!
Here are those two diodes on the P700 board diagram. Kind of interesting to see how they connect into the circuit.
H705 H706.JPG
 
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