philips lcd tv powers on ok backlight on sound on no display

[shelby5041]

hi

i want to thank everyone in here who has helped me on other tvs

i just got a tv today...its a 32 philips lcd made in 2010

it powers on fine...backlight comes on...sound is on

but there is no display at all..no picture..no onscreen menu

i have checked voltages from ps to main board and all check good...also fuse on tcon is good and i checked the voltage at the fuse on tcon and its approx 13v....there is a blue led light on the tcon that lights up when tv powered on have reattached cables on tcon and still no display

how can i rule out a main board issue?.....are there any other basic tests that arent too involved to make sure its not a main board issue?..and is there anything i can do to rule out tcon being bad?

thank you

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

model 32PFL6704D/F7

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

Picture and the number of the T-CON board? There should be some Voltage test points on the T-CON that you can check.

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

6871L-1925A

see attached photo of board

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

This TV can do 120Hz, so is there another board (FRC) between the main board and this T-CON board?
Can you upload the whole back side of the TV so we can see how all the boards are connected together?
I also do not see '6871L-1925A' printed on the board.
This one matches your board:
http://www.shopjimmy.com/lg-philips-...-con-board.htm
Looks like the FRC is done on the main board:
http://www.shopjimmy.com/catalogsear...2PFL6704D%2FF7

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

yes 120hz and no board in between main and tcon.........i will see if i can take a pic now..im at work with tv here....shop jimmy online video said if there is sound then typically its a tcon issue and not main

is this somewhat true?

.

[Shinju]

Re: philips lcd tv powers on ok backlight on sound on no display

LG t-con 120hz is processed on the mainboard.

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

Yes and no since the video processor on the main can be bad. Something like this I would try a new T-CON.
If you have scope then you can look at the LVDS signals and clock signals to see if they are present.

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

yes thats the tcon..same one as the photo i supplied....and this is a high end tv at its time...1080p 120hz subwoofer built in...very nice tv....600.00 when new....

here is a photo of back of tv.....i really want to fix it...its a very nice tv definitely not low end

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

but remember 120hz or not there is no on screen menu or anything...no display at all not just no video

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

here is the photo

any help would be appreciated.....i jsut want to find out how to know its tcon or main board with any testing thats not too involved all i have is a multimeter

thanks

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

If the main board does not send the LVDS signals or T-CON is dead, you will not see anything on the screen.

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

wouldnt the onscreen menu come up even if there was a video processing issue?

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

No. On screen menu is Video signal.

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

ok so there is no way to test tcon to make sure its bad? just using a multimeter?

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

ok thanks.....

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

No, you need to find out if the signals are being sent to the T-CON or not.

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

i dont like just swapping boards costs to much money..but i guess if there is no way to prove tcon is bad then i guess ill just buy one and see...if tcon doesnt fix it then i guess try a main board if that doesnt fix it then i guess panel is bad

i usually like ruling out boards and buying the correct part instead of just parts swapping but if thats what i have to do then i guess ill do it...

[shelby5041]

Re: philips lcd tv powers on ok backlight on sound on no display

well all i have is a multimeter...so i cant test the signals correct?

[budm]

Re: philips lcd tv powers on ok backlight on sound on no display

The LVDS signal are around 100MHz or more, you AC meter is probably good for 50~500Hz.

http://www.ni.com/white-paper/4441/en/
`