k7000 almost no red

JoeB1355

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This monitor did kind of work when I got the game and had no red i could see. Did a cap kit, reflowed cleaned the board then it was dead...

wiggle screen knob and I could hear static white knob flyback and then noticed cracks all around the knobs. So ordered/installed a flyback and now its coming up with almost no red. I can see it in the dark but almost nothing in the light

I swapped the transistors on neck board and put a new q1 on main board no change

red drive all the way up and red cutoff all the way down (that really didn't change anything). Turning red drive down did make the tiny bit of red go away....

Is the tube toast or is there something else it could be?

the crosshatch with the dots looked nice and white other white screen look good too -- I would think they would blue/green with no red....

lights on
20250907_210118.jpg

lights off

20250907_205707.jpg
 
There's preamp transistors on these chassis for each color. Look where the video signal comes in, there's three tiny transistors one for each color. I had one missing green once and everyone was saying it's the neckboard or the tube is bad and it was the preamp transistor. I think its like a 3n something, I got them at radioshack in a bag with all different ones back in the day when I needed it.
 
I think it was q1 2n3904. I put a new one in no help unless q1 is the wrong one?
Yup you got it I was just going from memory of like 10 years ago, I read the schematic and q1 is what I meant by preamp transistor. I'd look at q4 and all the other associated components in the red ciruit before ic1.
 
Hmm to be sure you really need either a known working k7000 chassis to try or a rejuvenator/analyzer. Or a good tube to put this k7000 on to see if the weak red follows.

For this one just reading from what you tried so far and tested and the pictures I fear the red gun might be weak in this tube.
 
Hmm to be sure you really need either a known working k7000 chassis to try or a rejuvenator/analyzer. Or a good tube to put this k7000 on to see if the weak red follows.

For this one just reading from what you tried so far and tested and the pictures I fear the red gun might be weak in this tube.
I tore apart another game and tried the chassis on that tube and it was fine. So I guess the red gun is weak... Anyone around Knoxville goa a rejuvenator that would be willing to try it on my tube? or alternately anyone got a old tv to harvest a tube from with the right ohms near me?

TVs are getting harder to find for me least and buying a bunch just to get lucky isn't really worth it

at least the chassis is good and rebuilt and I know what I need now
 
I tore apart another game and tried the chassis on that tube and it was fine. So I guess the red gun is weak... Anyone around Knoxville goa a rejuvenator that would be willing to try it on my tube? or alternately anyone got a old tv to harvest a tube from with the right ohms near me?

TVs are getting harder to find for me least and buying a bunch just to get lucky isn't really worth it

at least the chassis is good and rebuilt and I know what I need now
Im in north west Indiana so I probably cannot help you. It can be hard to find a good tv tube for swap, however most 25" tubes especially early to mid 90s even up to the early 2000s will usually work either way with the k7000 that chassis is more agreeable than any. Check marketplace or pawn shops thrift stores etc. the k7000 can also replace a lot of other arcade tubes directly like cgm 2500, u2000, u5000, k7400, hantarex polo, i believe eeven neo tect standard res tubes.

Maybe someone in the area has a rejuvenator for you to try I would say that its a good candidate to try one because you do still have red its just kinda weak
 
If you know the models of tv to look for within one or two TVs you could find
a good tube. Look at flea markets, goodwills, electronics recycling centers, Facebook marketplace/craigslist, and if you're willing to cough some cash eBay. Also since this tube has a little red, see if someone can rejuvenate it. Look for the cheapass black plastic TVs from the late 90's to early 2000's, Orion brand usually has a tube that'll work.
 
Im in north west Indiana so I probably cannot help you. It can be hard to find a good tv tube for swap, however most 25" tubes especially early to mid 90s even up to the early 2000s will usually work either way with the k7000 that chassis is more agreeable than any. Check marketplace or pawn shops thrift stores etc. the k7000 can also replace a lot of other arcade tubes directly like cgm 2500, u2000, u5000, k7400, hantarex polo, i believe eeven neo tect standard res tubes.

Maybe someone in the area has a rejuvenator for you to try I would say that its a good candidate to try one because you do still have red its just kinda weak
are you seriously? I'm from the south suburbs. I was just back home last week. lol
 
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