Philips CRT too bright and focus issue

Mike Fix

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I adjusted the control panel controls as far as they can go, but the brightness is still too bright. I can't get the blacks black.

It's fine when it first turns out, other than out of focus, but after about 20 minutes it get bright like the picture shown and then comes into focus.

Any help would be appreciated!

Thank you!

-Mike
 
Probably your flyback. The problem is called "drifting" which is after the monitor "warms" up the brightness and/or focus go out of whack.
 
point of emphasis: K7400s were made with multiple manufacturers of tubes. the tube doesn't matter. it borders on amusing and agonizing when some greenhorn rolls up in here like "SEE I HAVE AN RCA TUBE". no. video game monitors were literally built with consumer TVs. the TV part doesn't matter at all. neither do the Wells-Gardner labels.

I hope you've learned the last couple weeks that this isn't exactly easy to jump into. if it were then I wouldn't have had my job the last 17 years.
 
point of emphasis: K7400s were made with multiple manufacturers of tubes. the tube doesn't matter. it borders on amusing and agonizing when some greenhorn rolls up in here like "SEE I HAVE AN RCA TUBE". no. video game monitors were literally built with consumer TVs. the TV part doesn't matter at all. neither do the Wells-Gardner labels.

I hope you've learned the last couple weeks that this isn't exactly easy to jump into. if it were then I wouldn't have had my job the last 17
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I adjusted the control panel controls as far as they can go, but the brightness is still too bright. I can't get the blacks black.

It's fine when it first turns out, other than out of focus, but after about 20 minutes it get bright like the picture shown and then comes into focus.

Any help would be appreciated!

Thank you!

-Mike
mecha will help you. He knows it all. I mean everything
 
@summersquall22 I don't know everything lol but the focus/brightness drift issues from my own experience affect K7400/7500 and Neotec 2515C for sure. that's one particular instance where you need a new flyback.
 
point of emphasis: K7400s were made with multiple manufacturers of tubes. the tube doesn't matter. it borders on amusing and agonizing when some greenhorn rolls up in here like "SEE I HAVE AN RCA TUBE". no. video game monitors were literally built with consumer TVs. the TV part doesn't matter at all. neither do the Wells-Gardner labels.

I hope you've learned the last couple weeks that this isn't exactly easy to jump into. if it were then I wouldn't have had my job the last 17 years.

@mecha, you are so right about this not easy jumping into this. I also have to say thank you to you and everyone else here that have been very welcoming and helpful.

This has been very helpful to my mental health, having something completely outside my normal life to work on and enjoy. As silly as some of repairs have been, like adding buttons, or cleaning a very poorly operating millipede trackball, some random soldering here and there, and the happiness seeing these thing working again is irreplaceable. It's also sort of meditative working on these games which I also find calming.

Is this a K4700?

So I know what parts to order.

Attached is a photos of the board on the back of the tube.

THANK YOU!!
 

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@mecha, you are so right about this not easy jumping into this. I also have to say thank you to you and everyone else here that have been very welcoming and helpful.

This has been very helpful to my mental health, having something completely outside my normal life to work on and enjoy. As silly as some of repairs have been, like adding buttons, or cleaning a very poorly operating millipede trackball, some random soldering here and there, and the happiness seeing these thing working again is irreplaceable. It's also sort of meditative working on these games which I also find calming.

Is this a K4700?

So I know what parts to order.

Attached is a photos of the board on the back of the tube.

THANK YOU!!
K7400. as indicative by the presence of C729 (the large bipolar cap in front of the HOT, I could tell from one of the earlier pictures)

you would be moderately disappointed with a K4700 for this application...

the good news is the K7400 is more reliable than the U5000 that came before it. usually the worst that happens is the original flyback goes bad and you get focus/brightness drift. if it does go down though, you have several options for fixing it. it's not really a user friendly model for beginners. I've worked on dozens of them over the years and I don't want to be bothered with them anymore.
 
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