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2220B phono issue

need2boat

need2boat

New Member
2020B phono issue

I was hoping to get some help diagnosing a problem when I use the phone selection. I've tried 2 different record players and I'm getting intermittent noise and slight pops of varying loudness.

What I've tried so far:
changed speakers
Cleaned all RCA plugs and connections.
Changed out record player.
Checked ground at both record player and 2220B

I only get this when I use phono, it happens often but not always. If i lift the needle when its happening I will still hear it.

I'm new to vintage electronics but fairy handy so if this is over my head I do have some local repair shops in the South NJ area.

thanks

Joe
 
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Hi and hope the following can help. I have repaired quite a few marantz receivers (and BTW I am guessing you are talking about a 2220b as the 2020b is a tuner). I have often found the transistors are a source of phono section problems especially the 2SC458 transistors. You should have 2sc1328 transistors in this model. Also you may need to replace the tantalum capacitors, ( the little blue ones) can be a problem. I usually just recap and put new transistors in. I use an electrolytic to replace the tantalums of the same value or higher voltage. Not too hard to work on and high probability of success. Many here can help as well.
 
Thanks you, you are correct. I could not figure out how to adjust the post title.

So just to back, because I'm someone new to this. we are talking about the transistors on just the phono board all the boards?

Joe
 
Hi Joe, Just the phono board as this is where it is isolated based on your post. A ksc1845 should work here for subbing out the 2sc1328 and I recommend Silmic II capacitors, same value one bump higher voltage. I will check if it is the same legs for both transistors.
 
Hi Joe, a good resource is the AK database, just google those two words "AK database" you can get service manuals and sometimes parts lists. I see 6 x 2sc1328 transistors, 2 x 2.2uf 25v capacitors, 2 x 22uf 25v capacitors, 2 x 47uf 16v capacitors and 1 x 100uf 50v capacitor all that should be needed. My error , no tantalums just these electrolytics and these transistors should be all that is needed in general. Just make sure to order from Digikey or Mouser as a general rule. Good luck ! Let us know if this works.
 
Hi Joe, no problem, one tip from the school of "hard knocks": take a picture or draw out the layout before doing the work.

The circuit boards are not always marked correctly for capacitor polarity, transistor layout etc.

Prior to doing this I have ended up with blown capacitors, no sound etc,( but still able to be reversed and corrected).

Good Luck!

Scott
 
need2boat said:
Thanks you, you are correct. I could not figure out how to adjust the post title.

Joe
Click to expand...

At the top of this post, on the right click on "Thread tools", you can change the title there.

I would delete one of the two back to back posts for the same topic. It makes things alot more complicated having to go through two posts to see what's going on.
 
Last edited:
bryans12v said:
At the top of this post, on the right click on "Thread tools", you can change the title there.

I would delete one of the two back to back posts for the same topic. It makes things alot more complicated having to go through two posts to see what's going on.
Click to expand...

When I click on thread tools. The only option I can effect is "add poll". I can't edit the title or thread.
 
Ok I've got everything ordered. As a matter of best practices should I recap then test to see the noise is still happening BEFORE I replaces the transistors or do it all while I'm in there regardless of the transistors being bad?
 
It's not hard to unfasten. I'd say to replace the transistors first then test. Once it's tested as at least no worse and hopefully quiet after, then go back in and do the caps.
 
So I got everything in the mail but the desolder tape didn't show up yet but I've got around here. Access to the board isn't bad but when desoldering should I just flip the receiver completely over or better to work on it's side.

Joe
 
Hi Joe , should not matter either way, I usually work with them on their side but have also had them flipped over for better views at times. Let us know how it goes !
 
An advantage of working on its side is that you will need to alternate access to top and bottom as you work. It's easier to swivel the unit on its side than it is to constantly flip it over. But some boards can be removed enough to swivel on the wires. In that case working from just top or bottom works out.
 
I picked up a very heavy duty "Lazy Susan" at a local thrift store and it works great for rotating my 2275.
 
Guys, Thanks for the tips. I'm in the middle of de-wall-papering my house, the ugly side of mid century homes but I made sometime to dig in. I tried working on the side it just wasn't working for my so I guess I'm a flipper! I got most of the caps done (still need to do the red tantalum) and getting ready to start on the transistors. I did some readying and viewing on line and a few people talk about making sure you get the 3 legs in the correct way? Are they marked like the caps

I think it was Scotteboy who was talking about the blue caps and replacing them. I took a few pic before I got started and made a cheat sheet which I attached. I don't seem to have the blue caps mine are red with a white dot. I still went ahead and replaced them.

Hopefully tonight I can get the transistors in and see if this really was the problem.. .

phono_board2220B.jpg Marantz 2220B Phono.jpg
 
Hi Joe, Looks like you are on your way! The transistors should be marked with E, B and C for Emitter, Base and Collector. Probably is ECB orientation and you just have to make sure you install the same way as the old one. There are ways of testing with a multimeter but if you go slow and orient correctly should be no problem. I usually draw out the new one to compare just to make sure but I did that in the earlier response to make sure the KSC1845 was a leg for leg match. Just orient the " flat side" the same and it should be no problem. Compare the schematic with the board once you are done for good measure and then fire it up. Work on the phono board should not require anything more to see if you get sound or not. If not we will help but I always start with seeing if the proper board voltage is present at the incoming power.
 
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