flikery picture with hissing sound when bright only

[GraphicMan]

Hello guys

I just replaced my faulty FBT with a brand new chinese one for my LG 29" RT-29FB75VE CRT TV

the replacement was not the exact model but it has same pin assignment and voltages

The tv worked perfectly with same exact super quality/contrast image
but I noticed that the image does flicker noticeably WITH a hissing sound from the FBT only when there is a very bright image is displayed or a sudden brightness like explosions in a movie or something

if I drop down the contrast/brightness from the menu (still nice picture) that issue never happens

the FBT replacement is a BSC26 - N2137 (6174V 5003Z)
my original FBT is 6174V 5003R

what does that issue mean?
Thanks

[Harvey]

Re: flikery picture with hissing sound when bright only

chinese

...

[R_J]

Re: flikery picture with hissing sound when bright only

Crap replacement flyback, try and find an original. This problem has been around for years. In a lot of cases the cheap replacements just do not work correctly. Higher brightness means more current has to be supplied by the flyback.

[petehall347]

Re: flikery picture with hissing sound when bright only

what killed the old one ?

[GraphicMan]

Re: flikery picture with hissing sound when bright only

Thank you very much for your replies

What killed the original: I dont know, but it arced after about 14 years of use, so it has to be replaced

[R_J]

Re: flikery picture with hissing sound when bright only

Those replacements are not made to the same spec. as original, but it could be that you got a poorly made one. If you can have it replaced with another one or have it replaced with another brand it might work better.
I have had replacements for Hitachi that did not work (narrow picture, poor hv regulation) I ordered an original and it worked perfect. I have also used those $10.00 transformers in some Sony's and they worked ok.

[Andrew F. Ali]

Re: flikery picture with hissing sound when bright only

Turn the SCREEN control on the FBT to the bare minimum to see a picture

[GraphicMan]

Re: flikery picture with hissing sound when bright only

Like I said, I lowered the brightness/contrast just a little (still have a great bright picture) and this issue does not show anymore

I am very happy with the picture at the moment, I have also glued a 12cm fan in front of the FBT/Heatsink around it in an attempt to keep it for a longer time

that fan is inside the cabinet and controlled via a switch outside, powered with a dc adapter, it helped lower the overall heat in that area

I just want to know, would that FBT live for some years or that issue is a sign of a soon failure?

it has been about 5 days now of work

[stj]

Re: flikery picture with hissing sound when bright only

it could also be a failing B+ capacitor that smooths the power to the transformer.

[GraphicMan]

Re: flikery picture with hissing sound when bright only

it could also be a failing B+ capacitor that smooths the power to the transformer.

Mabe not in that case because that never happened before with the original FBT