Discolored ceramic capacitors. Bad sign?

[Sergimm]

I am restoring an old Marantz 1050, and slowly measuring, recapping and cleaning its components. Yesterday when I was about to recap some electrolytic caps, I noticed that a couple of ceramic caps seem to have a yellow discoloration at the top (picture attached). Is that a bad sign? Of course I'll unsolder them and measure them, but since I know that even bad caps can sometimes pass a measurement test, I'd love to know whether I should just go ahead and order replacements for them.

 

[Ylli]

Pretty sure that is a marking placed on them by the capacitor manufacturer. But probably the only one who knows what it means is the manufacturer.

 

[Sergimm]

Ha, interesting. No other caps have markings like that. Maybe somebody in the Marantz forum will know, I'll ask there. Thanks!

 

[Ylli]

Looks like it might be a tempco.

 

[gadget73]

paint dot for some reason. Depending what they do it could be matching or temp coefficient. I'd leave them be.

 

[Binkman]

Nothing wrong with them. Seen that layout in schema's before, they don't see a lot of v's or current.

 

[Sergimm]

Thanks folks. The more I read about it the more likely it's a temp coefficient marking. I'll leave them be