White balance shifts when bright image displayed KV32S42

[TheRetroCarrot]

I recently RGB modded a KV32S42, for the most part things look great. The issue I'm having is that the white balance becomes significantly blue/green when the majority of the screen is white, dark colors and black fades as well. Any time there is a balance of color on the screen there are no issues. If I run the high voltage reg test in the NEC test program it's extremely visible.

Anybody have an idea of what might cause this? Capacitors somewhere? I'd be fine recapping the entire TV, but before doing so I'd like to know there's a chance of fixing this.

Thanks!

[tongshadow]

Normal CRT behavior.

[TheRetroCarrot]

Out of the 8 sets in my house at the moment this is the only on that exhibits this to a substantial degree.

[tongshadow]

Rule out the RGB mod by checking the behavior in composite/svideo or RF, if possible.

[TheRetroCarrot]

It's the same with either. I didn't notice it before since all I ran through this TV before and after the mod was some SNES games to test and 240p test suite. It's quite noticeable on a blank white screen, but I didn't really start to notice it until working in Windows with explorer windows.

I might just do a full recap before putting it in my cabinet regardless. It won't hurt anything and might extend the life of the TV a bit.

[bobrocks95]

My FV-310 does this to a noticeable degree.

[SuperSpongo]

I have a similar Sony that used to have this behavior. The tube was the problem: One of the three colors would crap out when a bright white picture was displayed, leaving the other two colors blasting on full brightness and thus tinting the image. I used a colorimeter to verify with the 100 IRE test pattern of the 240p test suite. You could see that the emissions of the green beam would go down with increased brightness. I even verified this by swapping the red and green channel to rule out electronics.
I rejuvenated the tube and it's absolutely phenomenal now! But rejuvenating Trinitrons is kind of risky from what I've read.

Not saying that this is definitely the problem in your case, but it could be.

[TheRetroCarrot]

My 27" or 32" FV-310 doesn't do this at all that I can visually detect. That's unfortunate if it is the tube. I guess it's also possible this particular model just has poor voltage regulation. I'd be curious if anyone with a similar AA-2D set displays this behavior.

[Josh128]

I have a similar Sony that used to have this behavior. The tube was the problem: One of the three colors would crap out when a bright white picture was displayed, leaving the other two colors blasting on full brightness and thus tinting the image. I used a colorimeter to verify with the 100 IRE test pattern of the 240p test suite. You could see that the emissions of the green beam would go down with increased brightness. I even verified this by swapping the red and green channel to rule out electronics.
I rejuvenated the tube and it's absolutely phenomenal now! But rejuvenating Trinitrons is kind of risky from what I've read.

Not saying that this is definitely the problem in your case, but it could be.

What brand and model rejuvenator did you use? Also, when it did its diagnostic, did it recommend rejuvenation or did you just do it regardless of its recommendation? Ive recently seen the posts Andy King had made on X/Twitter about a "Flash-EX" adapter that was sold with Muter CRT Analyzers in Europe. You use it after a rejuvenation to prevent the flashing and popping that always kills Trins and other unified inline gun designs post rejuv. Could end up being a thing, but I think he still has a ways to go to really prove that.

[vol.2]

I recently RGB modded a KV32S42, for the most part things look great. The issue I'm having is that the white balance becomes significantly blue/green when the majority of the screen is white, dark colors and black fades as well. Any time there is a balance of color on the screen there are no issues. If I run the high voltage reg test in the NEC test program it's extremely visible.

Anybody have an idea of what might cause this? Capacitors somewhere? I'd be fine recapping the entire TV, but before doing so I'd like to know there's a chance of fixing this.

Thanks!

Before having too much of a freak out about it, I have found that sometimes these issues can be fixed by doing a full color balance. At the very least you can determine exactly the extent of the issue

Get yourself a colorimeter. The Xrite DPT94 is typically available for pretty cheap secondhand. The main drawback to this unit is that the sensors age and you will have to do a black level calibration each time you use it. Then download HCFR and do a full setup. I have found that I typically get the best results when I turn the cut off (bias) controls all the way down, turn the drive controls to 50% or slightly lower, and then turn up the G2 until a color emerges (RG or B) and then go back down until it's just black again. Then go to the 20% step in HCFR and raise the other two colors until it tracks correctly for your chosen temperature. Then go to 100% and set that and go back and forth between 20% (adjusting cut off) and 100% (adjusting drive) until the set tracks within +/- 2 in HCFR. Try to keep the cutoff controls as low as possible throughout the whole process (turn up the G2 as opposed to using the cut off controls to compensate).

If during the process, it becomes apparent that it's impossible to balance the thing, then you have an electrical issue

Also, it's worth noting that sets are only deigned to get to a specific level of intensity ala white level. Typically about 120 Y cd/m^2. If you are trying to push the white level much higher than that, it will exhibit garbage behavior

[tongshadow]

Before attempting color balancing, turn contrast down and see if the effect occurs even at the lowest levels.

[vol.2]

Before attempting color balancing, turn contrast down and see if the effect occurs even at the lowest levels.

I would question anyone's ability to accurately judge color balance at <20 IRE by eye

[tongshadow]

Before attempting color balancing, turn contrast down and see if the effect occurs even at the lowest levels.

I would question anyone's ability to accurately judge color balance at <20 IRE by eye

Dim enough to still be "white" but not dark grey.
I dont know how high his contrast is, so in a world where people think "1000 nits isnt enough", it's a good idea to ask.

[SuperSpongo]

What brand and model rejuvenator did you use? Also, when it did its diagnostic, did it recommend rejuvenation or did you just do it regardless of its recommendation? Ive recently seen the posts Andy King had made on X/Twitter about a "Flash-EX" adapter that was sold with Muter CRT Analyzers in Europe. You use it after a rejuvenation to prevent the flashing and popping that always kills Trins and other unified inline gun designs post rejuv. Could end up being a thing, but I think he still has a ways to go to really prove that.

I also used the Müter. It does not recommend rejuvenation, but I concluded that it must be electron emissions. The rejuvenation process on the very last models (95, 2005 and another one that's a 95 in benchtop form factor) is automated unlike the crusty B&Ks you see on arcade Youtube channels.

I'm actually in contact with Andy, recommended and proxy-bought the Müter for him. He discovered the Flash-EX thing in the manual and it sounded really interesting to me too.
After rejuvenation, I also heard a loud pop but luckily, the tube survived.

[matt]

What brand and model rejuvenator did you use? Also, when it did its diagnostic, did it recommend rejuvenation or did you just do it regardless of its recommendation? Ive recently seen the posts Andy King had made on X/Twitter about a "Flash-EX" adapter that was sold with Muter CRT Analyzers in Europe. You use it after a rejuvenation to prevent the flashing and popping that always kills Trins and other unified inline gun designs post rejuv. Could end up being a thing, but I think he still has a ways to go to really prove that.

According to Andy, there's nothing special about the FlashEx - it just connects all the pins to ground. You could easily make one with a spare tube socket and an alligator clip. The question is whether the success rate is from the FlashEx or the Muter device itself. Next time I find a burnt Trinitron, I'm planning to hit it with by B&K and a DIY FlashEx to see what happens!

BTW don't Google "muter flash-ex" unless you want some really weird porn links.

I agree that OP's problem is likely a tube issue. Having the color balance change on bright screens is not normal, especially on a 32" Trinitron.

[SuperSpongo]

BTW don't Google "muter flash-ex" unless you want some really weird porn links.

Hey, don't threaten me with a good time

[Josh128]

According to Andy, there's nothing special about the FlashEx - it just connects all the pins to ground. You could easily make one with a spare tube socket and an alligator clip. The question is whether the success rate is from the FlashEx or the Muter device itself. Next time I find a burnt Trinitron, I'm planning to hit it with by B&K and a DIY FlashEx to see what happens!

BTW don't Google "muter flash-ex" unless you want some really weird porn links.

I agree that OP's problem is likely a tube issue. Having the color balance change on bright screens is not normal, especially on a 32" Trinitron.

Im not quite understanding that electrically. If the cathodes are grounded, then applying anything more than ground potential to them should be immediately shorted to ground? What is the idea behind that process that supposedly makes the rejuve process safer for Trins?

Sorry about the "Muter" thing. Im way too lazy to figure out how to type the little punctuations above the u.

[matt]

Im not quite understanding that electrically. If the cathodes are grounded, then applying anything more than ground potential to them should be immediately shorted to ground? What is the idea behind that process that supposedly makes the rejuve process safer for Trins?

Sorry about the "Muter" thing. Im way too lazy to figure out how to type the little punctuations above the u.

I think you'd still get porn by searching for it with the umlaut. Google thinks you want "mature flash ex".

Apparently to use it, you remove the neck board, use the Flashex to ground all the pins, and run the TV with the anode cap in place. Supposedly the high voltage pulls contaminants off the electron gun and onto the getter, so later on when you run the tube for real there's not as much crap left in there to cause shorts.

[tongshadow]

Any late rejuvenator such as Sencore CR70, LCT-910A and B&K 490B should be gentle enough for Trinitron tubes.
Devices that use a steady current rather than shooting a charge at once are good enough for even sensitive CRTs.