Panasonic tx-50cx802b backlight and sound but no picture

[sordids999]

Hi
Bit stumped with this tv
Backlights come on and have sound but no picture
I have even removed each tcon ribbon just to eliminate the screen but nothing
Tcon fuse 12v both sides
Psu
Srv-16v =15.3v
Srv-5v = 5.0v
Srv-vcc= 27.6v

Driver board
Srv-led =40.7v
Srv-16v=15v
Srv-28v=27.4v

Thanks

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

More pics of underside of the psu

[Hamie]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Testing the tcon would be where I would start.

Upload a picture so we can see the test points.

[neilc6]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Panasonics usually have blink codes. I would connect one side of the tv at a time (looks like 2 ribbons per side) to make sure you don't have a bad panel.

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Picture uploaded of tcon board
I have tried removing two ribbons at a time but still nothing shows up on the screen

thanks

[dick_barton]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Is the set giving an error blink code ?

[Hamie]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Check
Vgl
Vgh
V33
V12

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Thanks hamie I'll check
Dick barton no errors it flashes green and stays green as if the tv is working fine

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

This is all I could find on the tcon

Vgl 0.35v
Vghp 0.00v
V12m 0.00v
V33dr 0.58v
Main tcon fuse 12v

[Hamie]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Looks like the tcon may be faulty.
Test those voltages again but with the 4 connections to the panel removed.

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

I will do thanks
Theres a few tcons on Ebay quoted as refurbished and spoken to a seller who's told me the screens are poor on these TVs as well

[budm]

Re: Panasonic tx-50cx802b backlight and sound but no picture

This is all I could find on the tcon

Vgl 0.35v
Vghp 0.00v
V12m 0.00v
V33dr 0.58v
Main tcon fuse 12v

So do you get the same Voltage readings without all 4 cables between T-CON and the LCD panel?

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Sorry I'm away at the moment I'll check in the morning

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Sorry for the late reply but with all 4 ribbons disconnected it's the same readings

Thanks

[Hamie]

Re: Panasonic tx-50cx802b backlight and sound but no picture

At a guess say UP1 has failed.
I know these boards are pretty cheap but would be interesting to know what actually failed.

Off chance that the panel may have killed the board so I'd test the new tcon without the panel connected when you first install it.

[sordids999]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Update
Tcon arrived today and the tv is now back up and working and testing

Thanks for your help

[Hamie]

Re: Panasonic tx-50cx802b backlight and sound but no picture

Good job