Buzzing/static on Philips GA437 turntable

Hi,

I have a Philips GA437 turntable that I've been trying to fix a buzzing noise on. It happens when the tonearm is lowered. The audio is extremely quiet and when I turn the volume on preamp up so it is audible, the static becomes louder. The static is in both channels. The static is affected/slightly changes when electronics plugged into the same circuit are turned on/off. Here are videos, pictures, and schematics: https://imgur.com/a/QQmKbAG

Things I've already tried:

1) Replace the RCA cable, including the ground wire which I've attached to the ground post on the chassis base and also tried attaching it to a screw on a receiver

2) Plug the power cord directly into a wall outlet and also into a power conditioner

3) Replace the 2 capacitors

4) Resolder capacitors and RCA cables multiple times

5) Replace stylus

6) Clean cartridge pins and reseating the wires

7) Replaced belts

8) Tried multiple records

9) Soldering ground wire onto red ground post and rightmost post (which it originally was soldered onto)

Any help/suggestions would be much appreciated!