Toshiba 47tl5154 no image just backlight

[ricosavy]

I have a toshiba led tv that will turn on and have a backlight but no image. How can i test it to see if my tcon board is bad or if i have a bad main board.any input is appreciated thanks.

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

Here pic board

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

Here pic power supply

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

Tcon board

[CapLeaker]

Re: Toshiba 47tl5154 no image just backlight

Pretty easy to check with an oscilloscope the LVDS, while turning on and off the menu on the TV all the time.

[budm]

Re: Toshiba 47tl5154 no image just backlight

At least check and see if the main board is supplying the Voltage to run the T-CON.

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

I seen 12volts on the tcon fuse(budm)
I dont have a oscilloscope that is can go to 100mhz just one that can do 20mhz not high enough.In future i will purchase one for now i can only check voltages(capleaker)

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

i replaced the tcon board still just getting backlight but no image on tv any ideas what to check

[Peter Chiu]

Re: Toshiba 47tl5154 no image just backlight

If you didn't see any LVDS signal on scope,open the LED screen penal....... U will find water stain (on one or two green boards with tab connect to LCD screen) clean with tooth brush and acetone .One of my friend DID change resistor and fuse and fix the TV.

Most-likely you have is Toshiba 47TL515U LED TV and you definitely need is the Main Board 75023298. ......

Pls give us a feedback, if you fix the TV......Good luck......

[budm]

Re: Toshiba 47tl5154 no image just backlight

The OP does not have the scope.
"I seen 12volts on the tcon fuse(budm)
I dont have a oscilloscope that is can go to 100mhz just one that can do 20mhz not high enough.In future i will purchase one for now i can only check voltages(capleaker)"

[Peter Chiu]

Re: Toshiba 47tl5154 no image just backlight

My Mexican friend (Jose Perez) teach me, put LVDS cable on the tongue and you can feel the signal....... But don't try at home ........

Next project 1: I will make LVDS tester in the future.
Next project 2: LVDS to VGA converter ,LVDS signal on your computer monitor.

[CapLeaker]

Re: Toshiba 47tl5154 no image just backlight

[QUOTE=Peter Chiu;547915]My Mexican friend (Jose Perez) teach me, put LVDS cable on the tongue and you can feel the signal....... But don't try at home ........

QUOTE]

I am guessing that's how your friend checks the main filter cap on the power supply to see if the PFC is working or not...

[budm]

Re: Toshiba 47tl5154 no image just backlight

He must have very sensitive tongue to detect 350mV! or just B.S.

From SONY T-CON info:
The LVDS transmitter contains a circuit to serialize the parallel data. The parallel video information along with
sync and clocking data are transmitted via twisted line pairs. Depending on the logic level, current is sent along
one or the other of the twisted pair of wires. The receiving end of the wires is loaded with a resistor (usually
around 100 to 120 ohms). The receiver detects the polarity of the voltage drop across the resistor to determine
the logic level. The current level swings in the wire are about 3ma with a voltage differential of around 350mv.
This allows for transmission of the video signal with minimal EMI.

"Next project 2: LVDS to VGA converter ,LVDS signal on your computer monitor."
http://www.ebay.com/itm/like/2213100...lpid=82&chn=ps

[Peter Chiu]

Re: Toshiba 47tl5154 no image just backlight

I also heard people says {My father used have a TV repair shop , he fix TV with screw driver.}........more than one people said that ...........(CRT TV has 30 kV )....This is a murder.....

I could never understand........

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

I have replaced the main board ,and tcon board still same problem no image just backlight.any ideas

[CapLeaker]

Re: Toshiba 47tl5154 no image just backlight

bad panel?

[Hamie]

Re: Toshiba 47tl5154 no image just backlight

If you remove one ribbon from the tcon do you get anything?
Then reverse the process.

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

I will try it

[ricosavy]

Re: Toshiba 47tl5154 no image just backlight

Ok discounted the right side the left was dark no backlight the right had back light then disconnected the left side had back light all the tv and could see some line on right side

[CapLeaker]

Re: Toshiba 47tl5154 no image just backlight

Is that model number correct? 47tl5154
I can't find a thing about it. So recheck. I see that there is another ribbon cable between the inverter and the t-con.