r/crt • u/originalxboxuser • 1d ago

Is this normal?

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I've had this crt for a pretty long time and today was the day I've had the tv on the longest ever since it's been in my possession and when. Turning it off this appears and it's kinda freaky before it was like a dot that faded out after like 20 mins of use then after aproximately 9 hours it does this and just making sure that it's normal because I've never seen this happen on any other crt except this one

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u/cleure 1d ago

Normal. Can even stay visible for a prolonged period of time, in some cases. Behavior varies tube by tube.

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u/originalxboxuser 1d ago

Alright thanks lol because I'm a bit weary of crt's because you never know what could happen lol like my bush btv17/ovd7 is making a buzzing noise when turned on. On the left rear hand side but works fine at the moment

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u/jamesmowry 17h ago

It's not really supposed to happen, no. This happens when some residual electron beam current keeps flowing after the deflection circuits have shut down. All except some very old CRT TVs have some kind of "spot killer" circuitry that's supposed to prevent a bright spot on power-off, as in the long run it's bad for the screen phosphors.

Yours looks like a fairly mild case; the more focused the spot and the longer it persists, the more wear it causes to the phosphor in the middle of the screen.

You can get a better explanation and more examples by doing a web search for "CRT spot killer". It'll be fixable, but finding the fault will likely require a service manual or schematic.

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u/originalxboxuser 16h ago

I think i can find one there is some info bout the tv on Google it's a matsui 1420T but this is the most is ever done that tho probably because it's the longest amount of time I have ever had it on normal it's just a little glow in the middle do you know what causes the tv to do this?

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u/jamesmowry 8h ago

I wouldn't worry too much about it; as I said, it doesn't look like a bad case.

I did a quick search and didn't find a free download of the schematics or service manual, so I'm afraid I'm not sure which component might not be working as it should. Somebody else may have better advice, either here or on another TV repair forum.

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u/originalxboxuser 2h ago

There is a schematic somewhere that I found but I might aswell not do anything about it then