Focus. What dictates it ultimately?

mann0mann

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So let me preface this by saying I do understand how to adjust the focus through the flyback on a monitor...so it's not that what I'm asking here

I've got a working k4900 that has just recently been recapped. The flyback however was not replaced. The chassis worked prior to the recap and I didn't feel it was necessary to do given the high reliability of k4900 flys.

However this tube has always produced a slightly soft image. I was hoping the cap kit might perk things up but really no change in that regard.

So what I'm curious is...does the flyback dictate the sharpness of the image entirely or could it also be tube related as well?
 
Has the face of the tube itself, been cleaned? I've seen people have similar issues, and that was the actual fix on a few of them. You'd be surprised how many don't give their tubes a good wipe down. Not saying that's your fix, just making sure you're not staring through a haze :)
 
Ha. Yep. Totally get that. :)

It's a game I fully restored/rebuilt. Have had it for some time actually. It's just always been a hair bit fuzzy no matter how I adjust the focus on the fly. Actually seems more soft in the center than it does at the outer edges if that means anything
 
So let me preface this by saying I do understand how to adjust the focus through the flyback on a monitor...so it's not that what I'm asking here

I've got a working k4900 that has just recently been recapped. The flyback however was not replaced. The chassis worked prior to the recap and I didn't feel it was necessary to do given the high reliability of k4900 flys.

However this tube has always produced a slightly soft image. I was hoping the cap kit might perk things up but really no change in that regard.

So what I'm curious is...does the flyback dictate the sharpness of the image entirely or could it also be tube related as well?

i don't think on that model the flyback replacement would do anything for you. i would check the tube itself with a rejuvenator and see how the guns and emissions checks out and maybe it needs a basic reactivate.
 
i don't think on that model the flyback replacement would do anything for you. i would check the tube itself with a rejuvenator and see how the guns and emissions checks out and maybe it needs a basic reactivate.

Thanks. I have a friend with a rejuvenator. Maybe we'll give it a shot one day.
 
if you had a K7400/K7500, then absolutely I would say flyback. 4900, I'm in agreement with everyone else it's probably the tube.

if there's crud on the guns you have to assume that there's going to be some blockage preventing the colors from hitting optimally. if you go the rejuve route make sure you lay the tube face down on a blanket and have a screwdriver at the ready to tap around on the neck. you'll probably get a nice show in the test mode showing you the levels while you're smacking it around. :)

I don't know if Buffett demonstrates that exact step in his video, but his videos are very helpful.
 
if you had a K7400/K7500, then absolutely I would say flyback. 4900, I'm in agreement with everyone else it's probably the tube.

if there's crud on the guns you have to assume that there's going to be some blockage preventing the colors from hitting optimally. if you go the rejuve route make sure you lay the tube face down on a blanket and have a screwdriver at the ready to tap around on the neck. you'll probably get a nice show in the test mode showing you the levels while you're smacking it around. :)

I don't know if Buffett demonstrates that exact step in his video, but his videos are very helpful.
This is great into as I have a K7000 with the same issue.

Scott C.
 
This is great into as I have a K7000 with the same issue.

Scott C.

if you have any flyback issues on a K7000, just replace it. you'll probably see a myriad of cracks above or below the focus pot. another interesting symptom I've found was a flyback that worked before, but post cap kit and patented Buffett-style reflow, the picture is just black. you'll see the little green or blue blip dot when you turn it off, but no image. a change of the flyback in 2 instances fixed it. kind of bullshit. K7000s are overrated.
 
if you have any flyback issues on a K7000, just replace it. you'll probably see a myriad of cracks above or below the focus pot. another interesting symptom I've found was a flyback that worked before, but post cap kit and patented Buffett-style reflow, the picture is just black. you'll see the little green or blue blip dot when you turn it off, but no image. a change of the flyback in 2 instances fixed it. kind of bullshit. K7000s are overrated.
I don't know if it's definitively a flyback issue, but do know I cannot get the monitor perfectly focused. It's literally been that way for over 10 years with countless hours of use. If that is the flyback, then replacement is an easy fix, along with a cap kit.

Scott C.
 
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