Transistors seem reversed on my Marantz 4300

MikeRam

Active Member
I'm rebuilding a 4300 quad receiver and am replacing the transistors on the PD01 tone board because they are pretty noisy. I started replacing the 2SC1345 transistors using the same orientation as the originals but then noticed that they are reversed from what the silkscreen on the board says. For example, for transistor HD02, it is labeled from left to right BCE but the spec sheets say that the transistor is ECB from left to right. What gives! I assume I need to replace them as they were originally soldered in but that seems wrong!

VE0_8882.JPG

2SC1345-Data-sheet.jpg

The layout in the service manual has it the same as the board.
PD01 Layout.jpg
 
On the old outhouse shaped 2SC1345 it is the bevel face that is the front, NOT the flat face with the writing C1345...
The transistor is correctly orientated/matches the service manual.
 
if they worked all those years i guess they are fitted correctly . all you have to do now is test the orientation of the old ones and new ones and install new ones correctly as in same as old ones .
 
the hip roof (as I call them) transistors are reversed to a standard to92. I am working a sansui 3300 with a similar issue only they are to92s - it could be the screen print is wrong, I worked a couple tuners where the diodes were installed backwards to the screen print. The final arbiter is to look at the SCM and determine where each leg is supposed to go and install accordingly. whats the worst that can happen? ;-)
 
This is one of those gotchas. This particular transistor was available in more than one package.

The first picture shows the "normal" package.

upload_2017-4-15_18-43-28.jpeg


The second picture shows the "unusual" package.

upload_2017-4-15_18-44-24.jpeg

As previously mentioned, they put the number on the "back" of the outhouse version and the front of the transistor is actually the beveled side.

So just to confuse us, it makes it look like the order of the leads is reversed. When in doubt a DMM or component checker can be used to verify the lead orientation. You can also do this by measuring the in circuit voltages.

And just to help us out, Marantz has included more than a few errors in their service manuals and silk screening.

Here is a link to Marantz service manual and silk screen errors as reported so far. I do not know if there are any listed for the 4300, but just a heads up what you see may not always be correct. Double checking is not a bad idea.
 
Thanks for that info guys. I would have never guessed that the flat section with print on it isn't the actual face. I'm replacing them with KCS1854's and they are oriented ECB from left to right . Looks like I'm going to have to redo some of the transistors I put in.

thanks again.

Mike
 
This is one of those gotchas. This particular transistor was available in more than one package.

The first picture shows the "normal" package.

View attachment 910545


The second picture shows the "unusual" package.

View attachment 910547

As previously mentioned, they put the number on the "back" of the outhouse version and the front of the transistor is actually the beveled side.

So just to confuse us, it makes it look like the order of the leads is reversed. When in doubt a DMM or component checker can be used to verify the lead orientation. You can also do this by measuring the in circuit voltages.

And just to help us out, Marantz has included more than a few errors in their service manuals and silk screening.

Here is a link to Marantz service manual and silk screen errors as reported so far. I do not know if there are any listed for the 4300, but just a heads up what you see may not always be correct. Double checking is not a bad idea.

That error link is no good.
 
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