TOSHIBA LCD 37ZV635DG No picture but sound and backlight

[nex91]

Hi guys,
need some help, on my TOSHIBA LCD 37ZV635DG i have no picture but i have sound and backlight works. After some testing,visual there are no signs of burns on any board BUT the measurements on the power supply board are almost all OL except standby (5v) and power tv (3v). You can see everything on the pictures.
I did also a flashlight test but i could not see any moving picture on the screen.
I also hear some little buzzing from a TCON board.

Thanks in advance

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Stock warning about DEADLY VOLTAGE on power supply and some inverter boards can have 1000 v, if I read it right, I would try maybe reseat t-con board both connections maybe clean the contacts with pencil eraser.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Can you double check your model number? 37ZV635DG

[budm]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Have the flat white cable between the LCD panel and the T-CON board connected one at a time to see if you will pictures on half of the screen or not.
BTW, Cold side Voltage: you are seeing 'OL' on the meter because the Voltage is too high for the meter to display, you will have to move the meter scale up to see which scale it will no longer show 'OL'.

[nex91]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Thank you both for the tips,you both helped me. First,double checked the model number,back cover says 37ZV635D and the stick by the motherboard says 37ZV635DG.
False alarm for the voltages... I have a multimeter with automatic range but i set it manual to lower value.
Now the voltages are ok, i have 12v,24v, 18v sound,5v standby and 3v power tv.
And a little progress with the picture, when i reseted the connections with the motherboard nothing happened. BUT when i removed left ribbon cable i have got right side of the picture,pure white,then i put it again and i still had the half of the picture but some blur. (look picture)
Then i removed the right ribbon cable and i have got white picture with two stripes (look picture).

So,what you think,is the problem with the TCON board?

[budm]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

So the squealing from the T-CON board goes away when you have one ribbon cable between the LCD panel and the T-CON connected one at a time?
You can try new T-CON.
We can at least test some Voltages on the test points on the T-CON board, you can see the test points label such as VCOM, VDD, etc. You test those test points without the two ribbon cables connected to the LCD panel and then with the cables back in place.
BTW, the T-CON picture is too blur to see all the test points.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Took a quick look on ebay theres one for 36 bucks free shipping. might find one elsewhere cheaper not sure. Havent bought any for a while not sure where the cheap parts are.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

https://www.ebay.com/itm/Toshiba-37-...MAAOSw4HNab9B~

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

I usually grab a board becuz i butcher everything I try to solder, lol.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

One of the members here might have one for sale.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

https://www.ebay.com/itm/Toshiba-37-...MAAOSw4HNab9B~

Not sure if this is a match, it says 37RV instead of 37ZV.

[nex91]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Do you think that changing the TCON board will solve my problem? Is there something else that could cause the problem?

[nex91]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

@budm
When i removed both ribbon cables,it stop buzzing, if only one is removed, there is still buzzing.
I've tested the fuse and i got 12v and some output test points and i got some voltages,on some points not...
Can you mark the test points on the new pictures which i should test?

[nex91]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Got new TCON and changing have NO RESULT... Same symptoms. Any suggestion?

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Got new TCON and changing have NO RESULT... Same symptoms. Any suggestion?

So same buzzing coming from new tcon?

[nex91]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

Yes... Everything is the same including buzzing

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

https://www.youtube.com/watch?v=yTnkOfwBGGE Tcon testing video, could be a faulty panel.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

https://www.youtube.com/watch?v=ocqnqmBxiqY Testing tcon, make sure you have 12 volts on the fuse, like hes showing.

[nomoresonys]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

If the tcon tests out good, then could be faulty panel or mainboard.

[budm]

Re: TOSHIBA LCD 37ZV635DG No picture but sound and backlight

You have problem on the panel, it is drawing too much current from switching power supply on the T-con so the inductor/s is buzzing.