How to repair your tCON board AS15F AS19F AS34

Often when a LCD TV has weird, saturated or wrong colors we are not sure if it's a TCON board problem or a mainboard failure. A common way to find out would be to verify if the TV menu shows the same problem, but since the menu doesn't have all the colors you might not be able to see it with this method.
So before replacing ICs or even whole boards, one of the first things we can do is to verify the gamma correction buffer output voltages named VGMA + number. They should increase (or decrease) in a continuous manner. If they don't the problem is on the TCON.
Described here is the measurement of these voltages and the replacement of a buffer IC AS19.
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[@Maria-fe2hm]

Great video, so helpful. Thanks!

[@mgjfile]

Mine become "negative" (inverted colors like) after few minutes, I have to try to replace the AS15-HF chip.
Thank you for the tutorial.

[@teddympoka1548]

Its has helped me in my dairy repairs .

[@MrHarrys123456]

this gamma ic doesnt need to be programmed if replaced?

[@tomtechtod9200]

No

[@GeorgeGeorge-xj2bc]

Any abnornal screen picture like solarized,dark,very white,wrong colours,high colour level but the screen shows a full raster in the entire area and if the AS15 is present in the tcon board then change it at once without any second thought.It is a buffer and related only with the picture quality.

[@Turbo-X]

What about when T-Con voltages are decreasing step by step, could be mainboard malfunction then?
T-Con is T400HW04 V1 40T05-C02 for Sony TV KDL-46EX728
Thank you

[@Turbo-X]

There is no gamma corrector chip

[@tomtechtod9200]

Ненад Шиљић depends on how the picture looks like. I rarely get Sony TVs and when I did it was either a panel fault or the mainboard.

[@Turbo-X]

It looks like this:
scontent.fbeg2-1.fna.fbcdn.net/v/t1.0-9/32972148_1777838998929303_5121789723576107008_o.jpg?_nc_cat=0&oh=db028edf47455db7adf49d216e08b5e6&oe=5B9BBEAD
scontent.fbeg2-1.fna.fbcdn.net/v/t1.0-9/32855167_1777839112262625_4406055916441436160_o.jpg?_nc_cat=0&oh=fc7a219c8d6a0b3a85f6b264e44b9dd1&oe=5B7BF58B
Can faulty panel work sometimes?
When it works, it needs about 6 sec with dark background to recover noisy and then about 10secs of light background to good picture.

[@sergiomagno228]

Muito bom o vídeo.

[@tomtechtod9200]

Valeu

[@jeevanbagul1230]

Nice all time consider,

[@RadheyShyam-pp9cp]

Ok

[@ilovelife18]

Definitely can't perform this repair with my shaky hands :/ oh well

[@borispahovic7114]

how can i contact you

[@tomtechtod9200]

u can't