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So I've run into my first "WTF?" moment in my arcade cabinet life. 
The "monitor" in my cab was built from a P538 chassis board, and a A63ADT10X05-1 bonded yoke tube from a TV.
I've put in a new cap-kit, replaced a busted flyback, replaced the HOT and VR after the flyback violently failed in November, horizontal width capacitor, and a horizontal width coil. (The one that was on my chassis seized up and cracked when trying to adjust it). Picture looked fantastic and everything was good.
Had it humming along perfectly fine ever since the cabinet was put together a few months back. (The monitor has been running without issue since late last year when I first put it together).
I hadn't turned on the cab in a while so I decided to play some games last week. It was quite humid around here last week, and I had shimmied my cab back into the corner of the room just a little bit. That's all that was different from the last time I turned it on though.
Turned the game on (Have my MK2 board hooked up right now) and hear the "dong" from the board and nothing yet on the screen. Pretty normal as it needs to warm up.
I then heard the opening music but still no image so now I knew something was up. Turned it off, opened up the back cover of the HS-5 and turned it back on. Heard normal monitor static and a barely louder crack, then saw the isolation transformer smoking! Unplugged everything and recently replaced the iso. No image on the monitor, no smoking iso, and no neck glow. Visually, the solder work on the board checks out fine and nothing looks like it has blown.
Fuse F1 checks out perfectly fine and closed, but at Resistor C301 where I checked the B+, I only got 1.0 mV or 7.0 mV. (1.0 mV if my negative lead is on one of the giant metal heat sinks on the board, or 7.0 mV if my negative lead is on the chassis frame that is connected to earth ground). So the board is getting power (I checked the AC voltage at the plug where the isolation transformer connects to the monitor, and that is perfectly fine 120 V AC) but it is not generating the B+ voltage.
Could this be the HOT that has gone for some reason? I just don't know why a sudden change in humidity would blow something on the board that was perfectly fine before. The new ISO doesn't get warm at all when it's powered on so whatever was faulty on the chassis has stopped eating up the ISO. It's also strange that the fuse on the board would not blow but the monitor isn't creating any B+. Just really, really, REALLY confused here.
The "monitor" in my cab was built from a P538 chassis board, and a A63ADT10X05-1 bonded yoke tube from a TV. I've put in a new cap-kit, replaced a busted flyback, replaced the HOT and VR after the flyback violently failed in November, horizontal width capacitor, and a horizontal width coil. (The one that was on my chassis seized up and cracked when trying to adjust it). Picture looked fantastic and everything was good.
Had it humming along perfectly fine ever since the cabinet was put together a few months back. (The monitor has been running without issue since late last year when I first put it together).
I hadn't turned on the cab in a while so I decided to play some games last week. It was quite humid around here last week, and I had shimmied my cab back into the corner of the room just a little bit. That's all that was different from the last time I turned it on though.
Turned the game on (Have my MK2 board hooked up right now) and hear the "dong" from the board and nothing yet on the screen. Pretty normal as it needs to warm up.
I then heard the opening music but still no image so now I knew something was up. Turned it off, opened up the back cover of the HS-5 and turned it back on. Heard normal monitor static and a barely louder crack, then saw the isolation transformer smoking! Unplugged everything and recently replaced the iso. No image on the monitor, no smoking iso, and no neck glow. Visually, the solder work on the board checks out fine and nothing looks like it has blown.
Fuse F1 checks out perfectly fine and closed, but at Resistor C301 where I checked the B+, I only got 1.0 mV or 7.0 mV. (1.0 mV if my negative lead is on one of the giant metal heat sinks on the board, or 7.0 mV if my negative lead is on the chassis frame that is connected to earth ground). So the board is getting power (I checked the AC voltage at the plug where the isolation transformer connects to the monitor, and that is perfectly fine 120 V AC) but it is not generating the B+ voltage.
Could this be the HOT that has gone for some reason? I just don't know why a sudden change in humidity would blow something on the board that was perfectly fine before. The new ISO doesn't get warm at all when it's powered on so whatever was faulty on the chassis has stopped eating up the ISO. It's also strange that the fuse on the board would not blow but the monitor isn't creating any B+. Just really, really, REALLY confused here.