NES has audio noise + short graphical glitches.

I got my NES (water damaged but self-repaired) a while ago, and it had some problems.
There were wavy vertical lines on the screen, but I fixed that by replacing all of the caps in the module, along with the 7805 with a 1.5A one so it would produce less heat. However, I am still getting audio buzz (higher amount of buzz on brighter screens) even if I unplug composite video.

Also, whenever I play Super Mario Bros., there are minor random graphical glitches on around half a scanline for one frame at a time (position is also random, but it only ever happens on a single scanline at any given time). I only ever noticed it with SMB, and I tested it with both my EverDrive N8 and Chinese multicart. This happened before I replaced the caps/7805 as well.

I also boiled and thoroughly cleaned the 72 pin connector, so it isn't that either.

There were a couple of rusted points on the CPU, but I reflowed them. I don't know if that has anything to do with it.

Since I have a flash cart, I can run any test ROMs necessary. I already ran the official Nintendo test ROM, and everything passed.

Also tried two different PSUs. My main one, which is a 3rd party one that outputs 9v AC @ 1.3A, and my modded Game Gear PSU (10v DC @ 850mA) that I use with my Super Famicom. No change.

 

Just ran the Sound Test in the 240p Test Suite and got reproducible visual corruption. This is unlike the other corruption I've seen in SMB.

Using 240p Test Suite 0.08.2.



EDIT: Rerecorded with a higher frame rate to reduce the black bars: