Marantz SD 9000 Compudeck PK21 Board Question

[Ryan Scruggs]

Hi, all!

I have previously posted about some issues I have been having with my Marantz SD 9000. I have replaced the notoriously bad optocouplers, and all belts and idler tires.

What I neglected to notice were the burnt out resistors on the PK21 board of the machine. I purchased and replaced these resistors, with the exception of one. Here is a picture of the section of the board in question before I attempted the replacement. The R516 resistor (inside blue box), despite my best efforts to photograph the board before I de-soldered the resistors, has been giving me problems.


As I have said, I have replaced (successfully) the remaining burnt out resistors, but now I cannot seem to figure out the proper connections that need to be made for the R516 resistor.

To aid in a solution, here is the schematic of the PK21 board, with the R516 resistor in the blue square:


If someone could clarify, in layman terms, the correct orientation and connections that need to be made to complete the restoration of the PK21 board, I would be eternally grateful! I also have a wire that has become un-soldered, and I am unsure of its origin, but that will be an issue for another forum post!

Thanks again!

 

[paul_ral]

I took this picture when I restore my SD 8020

and another one

These pictures were taken when I open the lid. It was very hard to restore this 8020 because more parts were missing and connection between PCB were wrong.as you can see.

 

[Ryan Scruggs]

I took this picture when I restore my SD 8020

and another one

These pictures were taken when I open the lid. It was very hard to restore this 8020 because more parts were missing and connection between PCB were wrong.as you can see.

I know, these things surely are beasts to try to fix! Sadly, though, I cannot see the resistor on your machine that's analogous to the R516 resistor on mine. I'm not entirely familiar with the similarities and differences between the 8020 and 9000 models. Does your machine have an R516 resistor?

 

[paul_ral]

Another angle

R516 is 10 Kohm one and is second resistor above R519 trimmer

 

[Ryan Scruggs]

I know, these things surely are beasts to try to fix! Sadly, though, I cannot see the resistor on your machine that's analogous to the R516 resistor on mine. I'm not entirely familiar with the similarities and differences between the 8020 and 9000 models. Does your machine have an R516 resistor?

You see how the R516 resistor has that jumper wire connected to one of the leads? That's how the old one was when I de-soldered it, so I saved it to use on the new R516 resistor. I have the jumper wire and one of the resistor's leads in the right place. I just can't seem to figure out where the other lead should be inserted based on the original pictures I took of the machine alone.

 

[Ryan Scruggs]

Another angle

R516 is 10 Kohm one and is second resistor above R519 trimmer

In other words, it almost looks, from my pictures of the original board, that the second lead of R516 connects to the left-hand lead of R517

 

[paul_ral]

So, you have two resistors in series making 15,6 kohms.

 

[Ryan Scruggs]

So, you have two resistors in series making 15,6 kohms.

I just didn't want to make the assumption that the resistors were in series. I'm relatively new to the electronics repair world, and I wanted to make sure I didn't ruin anything beyond repair.

So, you think I should go ahead and solder the other lead of R516 to the left handed R517?

Again, much thanks for your help with this. My go-to guy says he's burnt out on tape players, and I intend to fix this thing, even if it kills me!

 

[paul_ral]

That resistor is in Program Detector Circuit according Service Manual (I am looking in 8020 SM, 9000 has same architecture) so, I think is better to keep your board as it is mine.