WS55807 User vs. Service Convergence Question

[TvilleDude]

I've been reading a great deal about the convergence ICs and related components blowing in this and other models.

I've also been reading that "overadjusting" convergence can stress and overheat the ICs, causing them to breakdown even sooner.

Does this overadjstment apply only to user mode? If I do a service mode adjustment, on all 3 colors in both 480 and 1080, will that "reset" the user mode data, meaning there will be less stress on the ICs?

Since this is a 9 year old box, that still works and looks great, I want to treat it with "kid gloves". So anything I can do to put less "stress" on it can only be a good thing, right?

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[lcaillo]

You are actually MORE likely to overcorrect in the service level adjustments. Anytime you push an adjustment to where you get diminishing effects you are driving it too hard and need to back off.

[TvilleDude]

Thanks for your input Icaillo, much appreciated.

I guess what I'm asking, is it "better" to do some adjustments in service mode. For example, if I bring up the the white user convergence grid, it does look pretty good. But blue seems to be a little high on the left side. I'm pretty sure I can fix this by tweaking blue TILT and maybe VSTA in service mode.

Or I can fix it by going point to point in user mode and move blue down a little where needed. But to me, it just seems that making a bunch of point to point adjustments, could add up to more overall variation, and accumulated "stress".

The real problem is we don't know what the values are in user mode. In service mode we see a nice range of numbers that change everytime we hit adjust. But in user mode, all we see is the blue or red line move a little, we don't know what the "value" is from point to point. Is there a way to "reset" all those individual point to point values?

But what I'm really asking is, what's the best way to approach the best possible convergence, without making those poor old ICs work too hard...

TIA

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[lcaillo]

I think it is better to do everything in the service mode. That way, you have the maximum control and can minimize the point convergence corrections. When you save the settings, you also don't have to worry about losing them if someone does a consumer reset or if you have a power outage or other disruption to the consumer memory. Understand, however, with greater control comes the possibility of messing things up more, so only store the data if you are sure you have made an improvement that you want to keep.

The values themselves are mostly meaningless. You pay attention to what is going on with the image. I always center the positioning controls by measuring the dc offset at the output ICs an keeping it below about 50 mV. Then I center the image with the magnets on the yoke, and forget the numbers. They really don't matter if the image is centered and the offset is minimzed.

Other parameters need to be set for the best geometry and convergence. If you have one that you move and it has little effect, you probably have it out of range (they come this way from the factory many times). This is what causes inefficiency in the outputs. You want to back them off until you can see an effect, and make corrections in another parameter that affects the same thing, or live with the error. Many times, a nearby point, or a more general parameter will get you what you need.