CRT line deflection after high luma line

[maxtherabbit]

See the distortions noted by red arrows, can I adjust / fix it?

When I activate the OSD, the problem disappears. I'm guessing it's because the screen brightness is being dropped below normal min brightness?

[gray117]

You've gotten to the actual service menu right? ...You'll likely be able to tidy up some of that bowing too via geometry adjusts. Of course little difficult to tell what might be effecting with the interference issue if it disappears when in osd...

Ideally they'll be an ABL (automatic brightness level) setting somewhere. Or try lowering R, G, B 'drives'... Presuming your guess is correct Exact cause might be difficult to pin down if due to ageing etc.. On the outside chance check for simple stuff too - that there's nothing nearby that could be interfering or putting right at a sensitivity threshold - large girder/subwoofer/big power brick source etc.


What's the exact tv model? (Try and find service manual setting).

Common service menu codes, being a newer set try bottom one first:

[PWR OFF] ... [DISP], [5], [VOL+], [PWR ON]

-or-
[PWR OFF] ... [DISP], [5], [PWR ON]

-or-
[PWR OFF] ... [DISP], [5], [VOL+], [PICTURE], [PWR ON]

-or-
[PWR OFF] ... [i+], [VOL+], [PICTURE]

Probably need to then press '0''0' to save changes on newer sets.

If still you have no joy there will likely be an ABL potentiometer/screw near the tv neck gun on the inside somewhere if you're feeling adventurous...

edit:
***
re-reading topic title: what do you mean by high luma line? You're referring to the actual line drawn on the screen right?(first presumption, above stands)

... And not that this only occurs with luma sync hook up? (second thought upon re-read, above may not stand, perhaps best to sort before connecting to tv if other sync is fine otherwise)

(And third thought if second is actually the case, but real outside probablity)
...There have been one or two cases of some newer trinitron sets operating better with luma sync than c sync...

[maxtherabbit]

By "high luma" I just meant a line containing a large amount of bright pixels.

I have accessed the service menu and I have the service manual as well, but I was lost as to what to change when I got there. Can anyone recommend a good write up on CRT adjustments? The service manual lists out the setting names but doesn't really elaborate on their meaning. (Like, with pictures because what even is pincushion lol)

Thanks for the tip on ABL and the color drives, I'll play with them and see what I can do.

[gray117]

pin as in pinch ... opposite being bulge/barrel.

Give it a go and you'll see - if cautious take note/phone pic of initial values.

Decent indicator of what will help with what re: sony tvs.
http://www.neo-geo.com/forums/showthrea ... uggestions


Good doc explaining everything in more practical detail - less immediately useful, although does illustrate practical issues, but it may help if you hit a wall with what you can do with service menu settings, and perhaps most usefully it does let you know why you're changing what you're changing in the service menu and what it is compensating for in the 'how it works' dept:

http://www.arcaderepairtips.com/wp-cont ... v1.2.0.pdf

[buttersoft]

You see this on cheap universal chassis when you try to drive them hard against their beam-current limit, or it starts like this and the brighter you try to go the more scanlines distort after a bright white line. It's an HV regulation issue, i thought. Which might just meant the Sony is aging. Does the problem lessen or go away when you turn down the overall brightness?

[maxtherabbit]

You see this on cheap universal chassis when you try to drive them hard against their beam-current limit, or it starts like this and the brighter you try to go the more scanlines distort after a bright white line. It's an HV regulation issue, i thought. Which might just meant the Sony is aging. Does the problem lessen or go away when you turn down the overall brightness?

Yes, reducing overall brightness helps.

How difficult would it be to source the regulator if I wanted to replace it?

[gray117]

Afaik it's going to be more of a circuit involving (likely in this case) a resistor that's ageing. But it could be a capacitor (both relatively easy to source/replace, though less easy to diagnose unless it's straight blown/brokem) or anything else as part of a chain ... could even go all the way back to your transformer/flyback (less easy source)... although hopefully more of an end-of-the-chain tweak/component I'd hope.
...

Did adjusting the gain and/or cut offs improve/worsen the situation in either direction?

...

The thing is I'd hope this slight variation in brightness would be fixable in settings as a 'tweak' rather than necessarily something that warranted a 'fix' unless settings were maxed and/or clearly causing other issues.

The problem with something that might need a 'fix' is diagnosing where the issue actually lies.... and... as I suspect buttersoft may have been implying - this might be something of a design flaw that may depend upon the performance/suitability of several components in the set, and either be difficult to fully eliminate, and/or an issue that'll likely re-occur.

[maxtherabbit]

Afaik it's going to be more of a circuit involving (likely in this case) a resistor that's ageing. But it could be a capacitor (both relatively easy to source/replace, though less easy to diagnose unless it's straight blown/brokem) or anything else as part of a chain ... could even go all the way back to your transformer/flyback (less easy source)... although hopefully more of an end-of-the-chain tweak/component I'd hope.
...

Did adjusting the gain and/or cut offs improve/worsen the situation in either direction?

...

The thing is I'd hope this slight variation in brightness would be fixable in settings as a 'tweak' rather than necessarily something that warranted a 'fix' unless settings were maxed and/or clearly causing other issues.

The problem with something that might need a 'fix' is diagnosing where the issue actually lies.... and... as I suspect buttersoft may have been implying - this might be something of a design flaw that may depend upon the performance/suitability of several components in the set, and either be difficult to fully eliminate, and/or an issue that'll likely re-occur.

I haven't yet revisited the set, but hopefully the settings will be sufficient

[maxtherabbit]

Afaik it's going to be more of a circuit involving (likely in this case) a resistor that's ageing. But it could be a capacitor (both relatively easy to source/replace, though less easy to diagnose unless it's straight blown/brokem) or anything else as part of a chain ... could even go all the way back to your transformer/flyback (less easy source)... although hopefully more of an end-of-the-chain tweak/component I'd hope.
...

Did adjusting the gain and/or cut offs improve/worsen the situation in either direction?

...

The thing is I'd hope this slight variation in brightness would be fixable in settings as a 'tweak' rather than necessarily something that warranted a 'fix' unless settings were maxed and/or clearly causing other issues.

The problem with something that might need a 'fix' is diagnosing where the issue actually lies.... and... as I suspect buttersoft may have been implying - this might be something of a design flaw that may depend upon the performance/suitability of several components in the set, and either be difficult to fully eliminate, and/or an issue that'll likely re-occur.

the cut offs were set very much higher than the initial values specified in the FSM, I reduced them back to FSM values and the issue is greatly diminished but now the image is too dark.

red came down from 356 to 130
green came down from 275 to 90
blue came down from 209 to 72

I'm still fighting geometry issues as well, the service menu settings helped a bit but the upper left corner is still pretty droopy and the convergence in the lower right is bad