Is a tube rejuvination risky and does it shortens the life of the guns?

[ebo0763]

I have a Wells Gardner K7000. It's not bad but I would still like to optimize it with a tube rejuvitaton.

I've heard that it shortens the life of the guns. And could even break it. Could that happen while following the instructions?

Is a rejuvination inadvisable?

[boardjunkie]

If you don't rejuv it correctly there is a chance that you'll make it worse. Rejuv is for really bad looking dim tubes. If your rejuv unit has a "clean/balance" function, try that first. Use rejuvination as a last resort. Even after a rejuv, you never know how long it will look better. It is hard on the cathodes....

[ebo0763]

If your rejuv unit has a "clean/balance" function, try that first.

So is clean/balance suggested for any good working tube, just to optimize it?

[boardjunkie]

If the tube works fine as it is, then I'd just leave it alone. There really is no "optimizing" a tube. Tubes have a very finite lifespan. They look good until they get alot of hours on them and the cathode emission starts getting weak. Any kind of corrective action is kind of a band aid fix.

[fredster]

The way It's written in some of the Older arcade guru's notes is this:
This works best on tubes that have been in gun games or have been in cocktails.  Crap from the screen falls into the guns and shorts them.

This is stupid risky, so take all precautions not to kill yourself.

Take out the transistors in the neck board with the bad color (or for safety, all 3). Locate the screen voltage pin of the CRT socket.  Usually it's no7.  Put a clip wire on it.

Turn on the monitor, then turn up the screen brightness to full.

With the wire clipped to the voltage pin, momentarily touch the other wire/probe to the pin that has the problem (red green blue). If it works, you will see a small blue arc in the neck of the tube.

Turn the monitor off, then see if it has infinite resistance.  If it does, you won.  If not, do it again.

He says it's a 50/50 to fix the problem.  And once it's fixed, never mount it screen facing up again.

The best way, find somebody with a tube rejuvinator and do it with the tool.  Somebody has to have one.  Ask around.

 

[ed12]

crt tube's have a finite life span
10 year's is a normal
i have seen them go 20 but that is far and few between
in the 40 odd year's i have been doing electronic repair
i have had a 75% good rate to 25% fail

rule of thumb,turn screen up until u see retrace
then back it off until retrace goes away,look at pic if it look's washed out
or contrastie then the jug :as we call them: is on it's marry way out
that is when i would try clean/balance/reguv

ed

[Ken Layton]

It all depends on the make & model of the rejuvenator. Some are better than others. The Sencore CR7000, which was their last model, is all microprocessor controlled and seems to be the easiest and most effective.

If you have a 25 inch k7000 with a Zenith brand tube, these tubes are crap and rejuvenation will help. However, the tube won't last.

[corycet]

Hi Ken, I didn't hear you mention the good old b&k 467. Are you no longer a fan of b&k rejuvenater I like the 467, but I have been thinking of switching to the CR7000 beamrite, since they have dropped so much in price.

[Ken Layton]

I still use a B&K 467 all the time. I mentioned the Sencore one because it is more modern.

[ed12]

ol school is 467

caught me off guard to

ed

[boardjunkie]

I've had 467s for many years and they always do the job well.

[lilshawn]

I use a B&K 470. Its pretty good. Never had a problem. Be nice to have the gauge for each color though.