Trapeze on MS8-18A

[erzane]

Hi guys,
There is a small trapezoid geometry issue on my monitor. I found two pots which are locked with a sort of plastic rubber, so I cannot move them except taking them off. What do you think about it?

[Asure]

Tempting to pull off the rubber blobs and twist them a bit. I love twisting my knob.

Anyway, these a probably documented in a manual somewhere, i would suggest to figure out what they do before turning them..!

[erzane]

Temptation is always there I assume.
Btw, I cant find any manual for this 18A.
But question is: did dare anyone ever tryed to twist a pot covered by a rubber blobs?

[nem]

I don't think there's a trapezoid adjustment on these boards. Trapezoid adjustment can be done by realigning the yoke.

[erzane]

I don't think there's a trapezoid adjustment on these boards. Trapezoid adjustment can be done by realigning the yoke.

I thought the yoke was for convergence only. Pls check this:


Anyway, I discovered those two pots are H. SUB1 & H. SUB2 (I already heard about these before but don't remember for what they are)

[nem]

I thought the yoke was for convergence only. Pls check this:

The yoke is the whole cone shaped thing that's in the red square and to the right of it. The rings are for static convergence.

You need to unscrew the clamp at the base of the yoke and remove any glue that's at the base and at the end on the rubber wedges. Remove said rubber wedges. After it's free to move, you need to tilt the yoke, find the sweet spot where it's nice and center and reinsert the rubber wedges. You need to do this while the monitor is on. The terminals you have circled in red can have some thousand volts going through them, so honestly, if you're at all apprehensive about it, leave the whole thing as it is and just accept the slightly crooked picture.

Required reading:

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

[erzane]

Thanks for your precises explanations and for this pdf, which is a great document.
Fortunately, I don't see any rotation issue, so no need to take the yoke off. Btw, it's sure it's better to leave it like that as you say.
So, I'll only try to put some magnet sticks to resolve this hook (''d'' on the arcaderepairtips pdf)

After I heard, ''c'' & ''d'' can be resolved with magnetic sticks. But I didn't understood why Karlsson said, p.26: ''...Electronic correction under digital control has the ability to provide asymmetrical compensation and trapezoidal balance.''
>when he talk about ''electronic correction'', does he mean across a pot?

[nem]

Yes, but not all chassis are created equal. Some have more adjustments than others.

[erzane]

Yes, but not all chassis are created equal. Some have more adjustments than others.

I see

[Sunder]

What is this game by the way?
https://img15.hostingpics.net/pics/530748DSCN9684.jpg

Why is my memory so bad now?

[Wurstkopp]

Why is my memory so bad now?

Dry solder joints.

[Sunder]

That's actually a good one. Imma use that.

[erzane]

Acrobat Mission - UPL 1991