What are these on the sound board.

THat bottom resister looks burnt ?
Is it possible they're both bad and someone did a repair by adding resistors over them instead of soldering them in ?
If you have a dmm, disconnect the hooks and try to measure the resistor they're over if it still has the correct value ?

Those blue squares are adjustable resistors known as pots. They would be used on a sound board to change the output volume of the speech or background sounds. You can remove them with out issue. Someone wanted adjustability without making it permanent.

Wasn't there actually a thread on Pinside talking specifically about this mod several months back?

Maybe but I didn't see it.

What do you mean? Can you describe what exactly happens? Or possibly record a video, if that's easier?

That is a mod to lower the gain of the amplifiers. The stock amp gain on some Sega and early late model Sterns (right after they bought Sega) was set high (so presumably the sound could get loud enough in an arcade) and they exhibit buzzing sound from the speakers at idle. This buzzing is very noticeable in the quiet home environment. Reducing the amp gain lowered the buzzing so it isn't as annoying.

https://groups.google.com/g/rec.games.pinball/c/RiqCixRjptI/m/c3jTUzOgqdYJ

I have this in the PinWiki...but I never found a picture.
capt_pinball, Can I use your picture?

Someone made a more professional looking mod that did exactly the same thing.
I changes the resistance value of two resistors.
See: https://www.pinwiki.com/wiki/index.php?title=Sega/Stern_White_Star_Repair#Loud_Hum_and.2For_Distortion_at_Low_Sound_Levels
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Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info