A problem I notice on many TV's
 

Sometimes, especally if there are bright areas in the picture, a TV's picture will distort a bit. The best example of this is straight bars that end up curving a bit when the picture gets brighter.

The 25" Samsung TV I found awhile back does this. It kinda annoys me as I've been using it as a computer monitor. When a window pops up, the sides of it are curved inwards, making it look slightly trapezoidal like.

I notice many TV's that do this, so I'm wondering if it's an actual problem, or just a characteristic of the design? I know TV's aren't designed as good as computer monitors are...

The bending of vertical lines occurs when the contrast and brightness are jacked up too high, and the HV supply lags making the picture 'bloom'.... Actually I have noticed this on many sets, old or new, and if the power supply's electrolytic filters are changed out it can make a world of difference.

Well, I don't have the brightness set very high on it. The factory default is actually a bit higher then what I have it set at.

Are the power supply's electrolytic filters those large caps that need to be discharged before removing them?

000

Well, this TV is a few years old. It was made in 2001. If something's drifting out of spec, I wouldn't mind fixing it before it becomes a huge issue.

So are these the caps that are large and hold a high voltage even after the set is unplugged?

They hold some voltage. Not a ton, like the picture tube. Discharge them before you remove them though, just to avoid an unpleasant zap.

And yes, this is pretty normal - replacing the filters should help, but you may not be able to get rid of it entirely.

-Ian

Oh I know it wouldn't be perfect. I've never seen a "perfect" TV. but this tv is "good enough" and has very vivid color, and since replacing the filter caps wouldn't do any harm...

I might just do that.

Don't get your hopes too high about changing caps, but try it if you want to.

Also, a terminology problem - you've been saying "brightness", but it's the "contrast" you need to back off on to reduce the beam current and reduce this problem.

Edit: or "Picture" control if that's what it has

old_tv_nut... thats true... Interestingly enough, Sony's usually have better regulation IME, and they're the ones which call contrast 'picture' . Some older Zeniths used white level/black level, which is without a doubt the more accurate name for the controls...

If I wanted to stiffen up the supply, I would increase the capacitance on the related lytics 'slightly' so as to not burn up any diodes. Say 15-20% increase or so, couldn't really hurt...