Blast City – wavy corners part 2

A lot of trial and error on the weekend 

 but still haven’t gotten to the bottom of it unfortunately 

I tried plugging in the vga (31khz) to my naomi universal and I didn’t get any wavy corners. Monitor is powered via the blast city, everything else is on the naomi

So I thought, I’d try it on my Blast in 31khz – same result, no wavy corners.

Tried it on my Astro City in 15khz with a new 15 te amp up cable and totally separate from the blast city (didn’t use the blast city at all) and unfortunately the wavy corners are still there even when using the astro city

Confirmed that the wavy corners aren’t there when using the MS8 on the astro city, so it’s definitely related to the monitor and the gut feeling is something in the yoke.

I took out the yoke again for further inspection and couldn’t really see anything outside of some residue from the tape

Upon putting the yoke back, I introduced MORE buzz

I also reached out to Jomac who stated this:

That appears to be caused by some sort of coil vibration, probably not something you hear though. It would be causes by loose coils windings or convergence strips vibrating against the coils, I would find something plastic you can get between the yoke and tube and see if putting pressure on different spots stops it happening, when you find it try putting some silicon on that part to absorb vibration.

After taking out the yoke again, inspecting it some more, this fell out and I thought bingo! This vibrating is what’s causing the buzz and interference on the corners.

Unfortunately, upon installing back it got rid of the buzz, but wavy corners are still there.

Going back to what Joey said, I thought those couple of windings that appear to be loose could be the cause, so I tried securing it with electrical tape to see if it had any effect

Unfortunately no effect 

So right now, there’s still a slight buzz and the wavy corners still exist.

I’m really out of ideas exactly trying to “secure/seal” the yoke as best as I can with silicone as outlined here – http://www.albyhus2.se/_eget/monitors/MS-2930-S/

One side of the yoke has “movement” when you press down on it unlike the outer side that has no movement