K7000 25" with left side banding

ArcadeDanger

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Hey folks!

I have a K7000 in my 3 player Rampart (also used to be a NeoGeo, and originally a PitFighter). Minor burn in on it.

Monitor has been Bob Boberts kit capped, replaced Flyback, pots on remote board replaced. HOT is original.

I'm seeing some banding on bright screens on the left side, most obvious on green in the snaps below; haven't been able to adjust it away.

I didn't try adjusting B+ on this monitor.

I do get a jumpy picture while playing at times.

Suggestions?
 

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I had those weird shadow lines on my K7000 as well. They seemed to be less apparent the more I unjumbled all the cables that run from the chassis to the neckboard. Now I can just barely see a faint vertical line way to the left but it's so faint I can't even get a picture of it.
 
lol, that's symptomatic of the flybacks Bob sells.

I can't tell you how many K7000 flybacks of his that crapped out after like 2 months. his hodge podge cap kits aren't much better.

I would trust Buffett or security before Bob in the future. Arcadecup temporarily doesn't have flybacks in stock.
 
Seams to me that a lot of these replacement flybacks SUCK! and fail so why not leave the original flyback in if it's working ok and not any signs of cracks etc...!
lol, that's symptomatic of the flybacks Bob sells.

I can't tell you how many K7000 flybacks of his that crapped out after like 2 months. his hodge podge cap kits aren't much better.

I would trust Buffett or security before Bob in the future. Arcadecup temporarily doesn't have flybacks in stock.
 
I can't imagine there are that many manufacturers of these flybacks anymore. Don't they generally come from the same place? I have had at least one K7000 fail of Bob's and a Sharp that I got from Arcadecup that was DOA. They just don't make em like they used to, I guess.
 
I can't imagine there are that many manufacturers of these flybacks anymore. Don't they generally come from the same place? I have had at least one K7000 fail of Bob's and a Sharp that I got from Arcadecup that was DOA. They just don't make em like they used to, I guess.

my flybacks do not come from the same manufacturer then any others and they are not even packaged the same and is done on purpose. most get them from a trading partner in china which is like a distributor and they shop around in china for the cheapest manufacturer for each batch and that is why there is so much inconsistency. its possible to have even mine bad (so far none and i am knock on more wood then you can imagine) LOL but i do stand behind my stuff and since mine are labeled and packaged different then everyone elses they are easy to id. by the way i have much better quality cap kits also and many hundreds of thousands of components in stock, so let me know if you ever need anything.
 
my flybacks do not come from the same manufacturer then any others and they are not even packaged the same and is done on purpose. most get them from a trading partner in china which is like a distributor and they shop around in china for the cheapest manufacturer for each batch and that is why there is so much inconsistency. its possible to have even mine bad (so far none and i am knock on more wood then you can imagine) LOL but i do stand behind my stuff and since mine are labeled and packaged different then everyone elses they are easy to id. by the way i have much better quality cap kits also and many hundreds of thousands of components in stock, so let me know if you ever need anything.

I'll definitely bookmark your site. Thanks.
 
Seams to me that a lot of these replacement flybacks SUCK! and fail so why not leave the original flyback in if it's working ok and not any signs of cracks etc...!
*sigh* The original flyback was working, but it had some pretty bad cracks (the pot had come off completely, and I superglued it back on). There was a separate thread that had lots of folks pretty insistent I replace it since it was going to turn into a tesla coil and lightning destroy the rest of my chassis at some point...

What is it exactly about the flyback that's causing this sort of behavior? Are you guys expecting it to go bad shortly?

Has anyone mentioned this to Bob? He's always stood by his product in my experience.
 
It would suck if it was the flyback after going through all the trouble to replace it!

My flyback is also from Bob and I had those lines much worse than yours as I mentioned before. Maybe try to reflow all the solder on the neckboard and move the neckboard cabling as far away from the flyback as possible.

I attached a picture of what my wiring looks like. I moved the white and blue cables as far a way as I could from the fly and the majority of the cables that come out of the flyback and it eliminated the problem.

I honestly just tried to move the cabling into a mass to recreate the problem but couldn't do it very well so it could be something else. Moving those cables around was the last thing I did before they disappeared though.
 

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My flyback is also from Bob and I had those lines much worse than yours as I mentioned before. Maybe try to reflow all the solder on the neckboard and move the neckboard cabling as far away from the flyback as possible.
Kevith, I'll give this a shot first as it's easy... I'll let you know afterward how it went...
 
Those replacement flybacks for the k7000 seem to work best for the later model k7000's . Those lines are more prevalent on the older boards.
 
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Kevith, I'll give this a shot first as it's easy... I'll let you know afterward how it went...

So today I got in and moved wires around all over; no love on getting rid of those lines/bars on the left side of the screen (or even making them move). The one thing I discovered is that green is cutting out on occasion. So I guess my next step would be to touch up solder on pin connectors and whatnot.
 
I've never worked on a K7000 but this issue on other monitors can be caused by the resistor in parallel with the linearity coil: look at the solder joints and reflow if necessary. Next I would check/replace high voltage polyester caps.
 
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I've never worked on a K7000 but this issue on other monitors can be caused by the resistor in parallel with the linearity coil: look at the solder joints and reflow if necessary. Next I would check/replace high voltage polyester caps.

the Bob replacement Polo flybacks do this very bad too. there is a certain combination of brightness and contrast adjustments that can make it go away though. I was never successful on the K7000 I did years ago.
 
I believe you and that's most probably the issue in this case. It's still worth mentioning that something similar can also be caused by the resistor in parallel with the lin coil since that can happen on any chassis, for example on this Hantarex MTC9000:

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So today I got in and moved wires around all over; no love on getting rid of those lines/bars on the left side of the screen (or even making them move). The one thing I discovered is that green is cutting out on occasion. So I guess my next step would be to touch up solder on pin connectors and whatnot.

Damn, well it was worth a shot. These lines are definitely weird in that I had really prominent ones that just disappeared when I was fiddling with that stuff. Maybe moving those cables around got me a better connection somewhere? I think I would touch up everything on the neckboard since that's easy enough and maybe everything around C57 too since that's the cap everyone says can outright cause this issue if it's bad.
 
Damn, well it was worth a shot. These lines are definitely weird in that I had really prominent ones that just disappeared when I was fiddling with that stuff. Maybe moving those cables around got me a better connection somewhere? I think I would touch up everything on the neckboard since that's easy enough and maybe everything around C57 too since that's the cap everyone says can outright cause this issue if it's bad.

yeah those resistors are very important. in some cases they can be the difference maker in the monitor working or not after a cap kit
 
Checked the neckboard (its really clean and no solder issues) and pulled the chassis out. Touched up some solder points that honestly looked and metered ok, but no change.

I couldn't figure out which resistor was in parallel with the lin coil (it is late and my eyes are getting cross) to verify M K Ls suggestion. Is it R99?

I'm tempted to order another Flyback from elsewhere to see if that makes the problem go away and prove Mecha right. Can probably use the Bob Flyback on another K7000 that has white knobs in it.
 

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