Sansui AU217II Clean Up (Rust etc.)

[avantbored]

Hey all.

Picked this up recently even though, I said last month, "I don't need more projects." Famous last words!

Just too nice of a price I guess. Anyway --

Single owner, but stored in a box. Doing the usual: Cleaning the pots and switches and lubing. Took off top and bottom plate, and, lo and behold...







What am I looking at here, guys? Rust? There was another rusty spot at the chassis near these spots that I was going at with vinegar, but I've never tried vinegar on a PCB. Wanted to consult more learned minds before I goof it up.


Thanks in advance --

Ryan

 

[p4spooky]

No, looks like crusty flux. Should clean up using a fiberglass brush and IPA. For any rust spots on the chassis I use Locktite rust dissolver for removing surface rust.

 

[avantbored]

No, looks like crusty flux. Should clean up using a fiberglass brush and IPA. For any rust spots on the chassis I use Locktite rust dissolver for removing surface rust.

Thanks! Ordered some fiberglass brushes.

 

[AudioModern]

You could probably try an old toothbrush in the mean time. I also used a plastic spudger with a point to get at thick build up and between solder blobs, but go easy on it.

 

[Scott Muni]

I place small pieces of paper towel on the pcb, and soak with IPA. Scrub the paper towel with a tooth brush. Soaks up the dissolved rosin.

 

[Puckster]

I do the same thing for dried bird droppings, bug guts and tree sap on my…ok, not quite the “same thing” more something similar…for my client’s cars that have nearly perfect paint, wet a microfiber towel w/ appropriate cleaner, lay it on offending contamination and a few minutes later gently wipe it off.

 

[avantbored]

Thanks all! I cleaned the bottom of the PCB, and @Scott Muni and @crv00's methods to great effect. There was some rust the bottom cover, as well as some of the interior plates that cover the tone and input boards.

Then I remembered there's a whole other side...

But I'm reading DC Offset now. Not healthy! 60mV or so. Unfortunately we're getting into stuff-above-my-pay-grade...

My tech is refurbing a Sansui AU8500 for me, so I may save this for him as part of a cash/trade deal. Happy to do some of the work for him on this AU217.