Panasonic TX-48CX400B Only backlight no picture

[Fixing222]

Sound works and screen is illuminated the back light but no picture.

The blink code when i turn on is 14 or 15 i think it is one of them im not sure

[nomoresonys]

Re: Panasonic TX-48CX400B Only backlight no picture

Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on. So we can see all the voltages and what they are doing. example in second link below if needed.

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on. So we can see all the voltages and what they are doing. example in second link below if needed.

So it was from top of tv way to bottom
11.98
0
0
0
1
0

TV ON
11
0
2.6
3.2
0
24.94
I'm not sure what you mean by pin number

[nomoresonys]

Re: Panasonic TX-48CX400B Only backlight no picture

Ok, I see you have one of those vestel powerboards, a lot of them don't seem to have the voltages marked on them, I better let one of the vestel pros help you. We don't see to many of those on this side of the pond.

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

Ok, I see you have one of those vestel powerboards, a lot of them don't seem to have the voltages marked on them, I better let one of the vestel pros help you. We don't see to many of those on this side of the pond.

Ok yeah it's not so pretty as others inside and not so easy hopefully incase it mattets to anyone I typed the board in and the part cn4 and got this
Image attaches
And the service manual/circuit diagram attached

[diif]

Re: Panasonic TX-48CX400B Only backlight no picture

Please stop posting pictures inline. Press Go Advanced then use the paper clip icon.

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

Please stop posting pictures inline. Press Go Advanced then use the paper clip icon.

Ok thanks for notifying me will do , yes take up lots of space sorry

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

After changing T-von and mainbiard it was none of them so maybe powerboard

[budm]

Re: Panasonic TX-48CX400B Only backlight no picture

Did you already try having ribbon cable between LCD panel and the T-CON board connected one at a time to see what you will get on the screen?

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

Did you already try having ribbon cable between LCD panel and the T-CON board connected one at a time to see what you will get on the screen?

Sorry not had much time to open it up but just got round to it, same thing. That was a good idea so this rules out the two tab boards (Driver boards) attached to the LCD if no display or could it still cause no display or a short just wondering

[budm]

Re: Panasonic TX-48CX400B Only backlight no picture

Checking Voltages on T-CON board test points will be next, I.E. VDD, VGH, VGL, etc.

[Fixing222]

Re: Panasonic TX-48CX400B Only backlight no picture

Only have VCC multiple times but will check all of those.