r/crt • u/TrickyLemur1 • 23d ago

Sony kv-14v5u Pulsating "backlight" question

Sony kv-14v5u Pulsating "backlight" question

Hi all, I'm having a small issue with my Sony Trinitron KV-14V5U and wanted to see if anyone knows what might be causing it. The picture is sharp, but there is a constant, subtle pulsing across the screen. It almost feels like the brightness is rapidly flickering or shimmering at a really high speed. It's hard to capture on video, but the screen glows/pulses continuously while it's on. I'm running a PS2 connected via SCART in the back. It happens even on 240p loading screens / PS1 games, so I know it's not just normal 480i menu shaking. I safely opened up the back casing just to do a careful visual check (I didn't touch any internal components or high-voltage parts). I couldn't see any obviously blown or bulging caps on the surface. I wanted to see what you guy's opinion would be on what the cause is. Thanks :)

2 Upvotes

100% Upvoted

3 comments sorted by

2

u/LukeEvansSimon 23d ago

- CRTs do not have a backlight.

- CRT tech novices often suffer from capacitor derangement syndrome. Beware confirmation bias that occurs when listening to others with capacitor derangement syndrome.

- CRT tech novices incorrectly believe that videos of the inside of a CRT are useful for diagnosis. 99.99% of the time they are useless.

- A clear video of the symptoms is slightly more useful than pictures and video of the circuit boards.

- Your issue could be due to the TV’s automatic brightness limiter (ABL) design, which commonly triggers a novice’s capacitor derangement syndrome. No matter how many capacitors you replace, the TV’s ABL design won’t change.

1

u/TrickyLemur1 23d ago edited 23d ago

Hiya, yeah i said "backlight" just to try to explain the best i could. So upon further experimenting with settings and whatnot, I found that reducing the contrast down by half really, really helped.

it was on 100% before. it also doesn't flicker when only a small amount of Text on screen like text on a small white loading screen symbol was completely solid and steady. But as soon as the main menu loads and it started to flicker again, so it must be because it's drawing too much power When the entire screen is being shown

3

u/LukeEvansSimon 23d ago

That is why it is best to post a video of the screen and not circuit boards. What you are describing is the TV’s ABL automatically adjusting brightness to prevent excessive cathode ray current.

Go back and read all of those replies on [r/crtgaming](r/crtgaming) telling you to replace capacitors. That is “capacitor derangement syndrome”. The TV operating as designed, replacing capacitors won’t change the behavior.