CRT Sparking Inside of the Tube/Screen

[BactaTankAddict]

This CRT was working fine for 3 months and then one day it started taking around a minute or two to turn on. Some days it wouldn't even turn on. It did this for about a week and then it started sparking inside of the screen/tube refusing to turn on.


Here's an example of it sparking inside the screen.

The sparking would act differently if my other monitor was turned on (24" 60hz lcd). The spark would disperse around the screen, rather than in the middle.


Here's an example of that.

Here are my theories as to why this is happening. One, the flyback overheated or isn't giving enough voltage to the screen. The wire that goes from the flyback to the anode cap had this weird black dust on it. This black dust was in the casing, around the glass of the tube, and on the flyback/anode wire. Not sure if this was just dust, or burnt marks, because it did have a weird smell...


Second theory is maybe the outlet isn't giving enough juice(?)


Third theory would be that the anode cap needs regreasing since there's a dark shaded circle around the tube's anode. I can wipe this circle off with my finger, not sure if I should be doing that so I left it alone.


The CRT casing is off at the moment, and I cleaned the motherboard & capacitors of dust (for the most part). It doesn't look like any of the caps are leaking. There's some weird blue stuff that looks like glue coming out of the focus and brightness knobs on the flyback, not sure if that's glue or leakage. Here's a photo of that.



What do you guys think? Is it the flyback or does it need to be recapped? Any information helps, thanks!

 

[bertus]

Hello,

Dust and moisture will cause sparking.
Also the humidity can cause sparking.
Turn off the monitor, wait for an hour and remove any dirt from the tube.

Bertus

 

[Bluejets]

In the bin.....must be over 25 years old at least.

 

[Martaine2005]

In the bin.....must be over 25 years old at least.

Hardly helpful.

A lot of my Hi-Fi is 1980s vintage.
Nothing new comes close.

I would take the back off the CRT and blow all the dust out to begin with.

 

[Bluejets]

Hi fi is not a crt screen when it comes to end of life given the extremes the latter works under.

 

[shrtrnd]

Sounds to me like your degaussing coil has an arc-leak between the coils, not the CRT itself.
Or maybe degaussing power circuit not de-energizing after it's initial activation.
This comes from one of those old TV repairmen that used to make house calls in the good old days.
Not something the new tech wizards are familiar with.

 

[shrtrnd]

ps:....
Also in the good old days, it was common practice (from your picture) for the tech in the factory to adjust the pots (your focus and brightness) for the correct alignment, and then put a dab of colored glue on the rotating knob to prevent somebody else down the
production line from accidentally changing the pot setting.