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CRT Rejuvenator

friedpotatoz

friedpotatoz

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Hello all,

Well long story short, I have an New Astro City and the monitor has this green tint and is dark. I sent the chassis to my buddy 300wins to check out and when he plugged it in his picture was bright and colorful. Last night I was messing around with the contrast, brightness, RGB etc and nothing really improved. I do notice that the browns are not showing up, especially when I play final fight. I've tested this with different games and they all look the same. So I think the next step should be using a CRT Rejuvenator.

I have never used one of these but I've been reading around and people tend to talk about the BK's? Using the #23 adapter, which is some what of a standard adapter? Would this be the right adapter for a NAC?

Which type of rejuvenator would be best? Anybody here have any experience working on these?

Heres a video I found about this: CRT Rejuvenator Help

Any help would be appreciated :thumbsup:
 
It sounds like a tube issue yea, but I notice you only said "chassis" what about the neckboard?
 
jassin000 said:
It sounds like a tube issue yea, but I notice you only said "chassis" what about the neckboard?
Click to expand...
Yeah, I first thought it was the Chassis that needed work so I sent it off to test it out. But these Rejuvenators come with different adapters to fit on various sized tube neck boards. So I was just asking which adapter would be best to fit my NAC monitor. Could the neckboard go bad as well?

Hopefully I am answering your question.
 
I use a sencore CR7000 and I love it. A rejuvenator can do some amazing things but should only be used as a last resort in some cases. It can be a horrible weapon in the hands of a OCD collector. Every time you rejuvenate a tube it strips a layer off of the cathode. So you only want to use it if you are sure you have a weak gun, etc. because there is always the chance you blow the gun if it's on it's last leg.

You can determine your adapter by looking it up by using the tube number on the back of your tube. 23 is a common adapter so it very well may be the right one.

Are you saying that when you turn your green gun all the way down there is still a green tint? Can you load a pcb that has a color test screen and show a picture?
 
Mitsurugi-w said:
Are you saying that when you turn your green gun all the way down there is still a green tint? Can you load a pcb that has a color test screen and show a picture?
Click to expand...
Yes slight green even when I turn it down, I will try to snap a pic when I get home tonight. Also its very dark and when I bump up the brightness the colors begin to bleed. Very muddy looking. The monitor has a slight burn, I can see the Metal Slug 3 logo when the screen is white.

Thanks for the info Mitsu!
 
yeah its a tube thing then. If the brightness is an issue too then a simple restore session could work. I haven't used a B+K but my Sencore has a restore mode. It just raises the voltage on the cathodes enough to remove oxidation. It is very safe. For more severe problems the rejuve function can be used. It rapidly sends a burst of higher than normal voltage to the cathode to attempt to literally "blow" the oxidation off of the cathode to restore proper function. Like if you had your hands on an electric fence when it was suddenly turned on. Or think of the scene in Jurassic Park where they are climbing over the fence and the boy gets stuck on it when the power is restored. Remember how far he flew? lol

One small test you can do is to turn of your monitor and very lightly tap on the neck of the tube near the cathodes with the butt of a screwdriver. It is possible there is some particles that have come off of the cathodes bridging between two pins in the neck causing a short which in turn is causing your green tint.

I'd like to see a picture of a color test on your monitor though.
 
How are the colors when you turn all three RGB pots on the neck board up and adjust the B on the flyback/chassis down?
 
Mitsurugi-w said:
my Sencore has a restore mode. It just raises the voltage on the cathodes enough to remove oxidation. It is very safe. For more severe problems the rejuve function can be used. It rapidly sends a burst of higher than normal voltage to the cathode to attempt to literally "blow" the oxidation off of the cathode to restore proper function. Like if you had your hands on an electric fence when it was suddenly turned on. Or think of the scene in Jurassic Park where they are climbing over the fence and the boy gets stuck on it when the power is restored. Remember how far he flew? lol
Click to expand...
Nice! I am hoping it's an easy fix. How much do these usually go for? I just saw one on ebay for $150 is that a reasonable price?
jassin000 said:
How are the colors when you turn all three RGB pots on the neck board up and adjust the B on the flyback/chassis down?
Click to expand...
I will test this out today or tomorrow.
 
friedpotatoz said:
I just saw one on ebay for $150 is that a reasonable price?
Click to expand...
Really depends on the model. I would try to find a B+K 490B or a Sencore CR7000 or CR70 (works the same but without the digital displays).

You can certainly find an older cheaper model but remember, it's been years since CRT TVs were common so a lot of them were probably never calibrated in their life. Last time I checked Sencore would still calibrate their units but I don't think B+K does, if they even exist anymore. Medical and military applications have kept the crt repair market in business but they are all transitioning to LCDs also. Military is always the last to switch over.
 
The CR7000, if one ever goes up for sale, will cost you slightly more than half the cost of your candy cab. After watching a highly respected KLOV monitor tech 'Buffet' demo the B&K 467, I picked one up with all adapters for ~$60 shipped. It even came with a universal adapter. Works great and is inexpensive. Check out Buffet's video where he simplifies the process for users and you can see the merits of this rejuvenator for yourself.

 
I paid $300 for my Sencore CR7000 but I also have over 30 CRT cabs. :P

The 467 might be better if you only have a few. If you can find one. Make sure you check the adapters included. You can always make your own adapter though.
 
I picked it up years ago as a BIN on ebay. It may have been more around $400 but that's a good price still and the reason I bit with the BIN. The really cool feature of a sencore is you can sign up for sencore-e.com and type in your tube number and it will tell you what adapter, voltages, etc you need. No need to search books or webpages for info like with the B+Ks.
 
Mitsurugi-w said:
friedpotatoz said:
Could the neckboard go bad as well?
Click to expand...
It COULD be a bad color drive pot but a lot of times they fail open and you'd have none of that color. You do see a change when you adjust the green pot on the neckboard, right?
Click to expand...
My experience is that failed transistors remove the color, and failed pots let too much color in. My money is on the green pots. If it were the tube, then both R and B would need to be bad for G to overpower them. Kind of unlikely. A rejuve can help with contrast though.
 
Well he could test the pot easily by swapping it with a different color. So if he swaps the pot with red and then suddenly has red tint then the pot is bad and an easy fix.

It won't help with contrast but can help by eliminating the need to drive up the brightness thus eliminating color bleed, etc.
 
I took some pics.

Regular and adjusted (some what)
Regular.jpeg


Brightness all the way up
BrightnessUp.jpeg


Contrast all the way up
ContrastUp.jpeg
 
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