If only I had a video of this to show you guys. WOW! I had finally gotten my monitor adjusted properly, and had recently replaced the full set of capacitors, including the B+ Filter Cap, the HOT, and the flyback. (Thanks Ian for the cap-kit. Was super easy to install). Everything went on incredibly easily and the image looked amazing. No cold solder joints, no shorts, no nothing.
Today, i was finishing up adjustments when my hand accidentally hit the yoke of the tube sending quite a bit of electricity into my right arm. Felt like I was stabbed and punched VERY hard at the same time in the same spot. Heh. They aren't kidding when they say that a CRT can REALLY hurt. Glad I followed the advice of everyone and always kept one hand in my pocket while adjusting the width coil to prevent a charge across my heart.
Anyway, while finishing up the width coil adjustment, i noticed that the neckboard wasn't seated fully against the neck of the CRT. You could see about a mm of pins all around the tube. This was likely from when I was first moving the tube and it slipped, causing it to lean onto the neck connector. I straightened out all the pins, but i guess I didn't straighten out the key plug enough. So i went and got that sorted out and had the neckboard fully onto the CRT tube. No pins showing.
As i've generally been doing, i turned the setup on and let my game play through it. This keeps everything warmed up, and is nice background noise for me.
While I'm sitting in the next room, i suddenly hear this loud screeching noise that was kind of like a record being scratched. I quickly jump up from my seat and run over to the room to see no picture on the screen and a TON of bright white arcs in the back area of the monitor. I nearly trip over my feet running for the power plug to unplug this thing. The smell of ozone filled the house.
After my nerves calmed down and I flooded the shout box here with my tales of woe, I went over to the tube, discharged it, removed the chassis, and closely inspected the CRT. Thankfully, it appears as though the vacuum is still present as the getter inside the neck is still a nice shiny silver color. I then looked over the board and saw no signs of physical damage. No funky looking capacitors, no charred parts, no overheated solder joints. It all looked good.
I then pulled out my multimeter and checked the HOT in circuit. Got readings of 0.490 on each leg so it appears as though the HOT was not damaged in any way by this failure. I'll test it out of circuit tomorrow as I'll need to remove it from the board per the problem I did see.
It looks like the flyback i had replaced was a dud. The ferrite cores that meet in the middle of the flyback itself and have a wire C-Clamp holding them together on the outside is INCREDIBLY loose. With the flyback on the board, it readily swirls around in all directions. i'm guessing the arcing I saw was coming from this. The flyback was manufactured earlier this year, but I guess something finally came loose and resulted in the catastrophic failure I witnessed.
Going to try to head to bed right now and sleep this off. Will do some extensive multi-meter testing tomorrow and will remove the flyback and toss it in the trash. I'm hoping that a new flyback on here will be a good one and won't result in an insane light show and soiled pants.