Crystal not oscillating in LCD panel

[brunofunchas]

Hello!

I have a LCD Samsung LE37M87BDX where the picture is black and white!

I have measured, in the main board, all of the crystals oscillators and one has 1Vdc in one pin and in the other 3,2Vdc and it is not oscillating. Do you agree that this component is defective?

Normally when I turn on the TV all the crystals will oscillate? Even if, they are associated to function that, in the moment we are not using it. Like an HDMI input.

Thanks,
Bruno

 

[dv_sa559]

Hi
you said main-board , which main ? pc or graphic card or monitor board ?

 

[brunofunchas]

Hi,

It is the board that receives all of the inputs of the LCD TV.

Regards,
Bruno

 

[dv_sa559]

last year i encountered by this problem that av input had problem which it shown black and white.
I survey other input ,all of them intact.
do you test other input?

 

[brunofunchas]

Hi!

I have tested all the inputs with the same result. My doubt is if all the crystals should be oscillating or some will be working and other not.

Regards,
Bruno

 

[dv_sa559]

According to your answer this malfunction related to all input.
i if you certainly know that one piece is bad,i think you should replace that.
Do you have any schematics of your tv board?

 

[brunofunchas]

Hi!

I do not have the schematics for the board!

I am using a FLuke 123 with a bandwidth of 20MHz and the Crystal is 28MHz. On the same board I have measured correctly one off 24MHz, Should the scopemeter detect the signal of 28Mhz? I think it should with a small attenuation on the amplitude!

Regards,
Bruno

 

[sdumas]

Hi Brunofunchas !

See if this is the correct service manual :
SAMSUNG_chassis_ GTU37SEN.pdf

If you have those voltages at the crystal,i guarantee you that is no oscilation present,anyway see if
the schematics are the right ones...

Regards

SDumas