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

[Shinju]

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

Break it down to panel level and look at the tft board is the only sure Fire way. My guess it's a victim of fluid damage, I had lg/VIZIO panels act like this and there was electrolysis on the TFT board from cleaner damage.

I wouldn't hook that new t-con up until I verified the txt board. Might fry the new one.

[shelby5041]

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

thank you thats pretty much what bud m said....and yes people do clean tvs with wrong cleaners and ruin boards when cleaner drips down onto the boards....if the board is bad...is this a repairable issue at all??? or tv is trash??

[shelby5041]

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

its just a lot of work tearing down to that level ......

[Shinju]

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

I have never been successful at it, I think lookingback (think that's his user name) was fortunate to fix a txt board but it really depends on how bad the damage is and if the electrolysis has damage the fused ribbon cable.

No idea until you see it. All the ones I have see. Have been pretty extreme.

[Shinju]

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

And I feel your pain on breaking down a panel to that level, the ones I did were 42" 55" ugh, had really good luck with 37" and below having good panels.

At least with a 32" it's relativity small not too many screws!

[shelby5041]

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

why is it that when i disconnect right ribbon on panel to tcon the right screen is bright white

but if i disconnect both left and right ribbons the screen is black and not full bright white?

[shelby5041]

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

i remmeber when i was doinf lcd monitor repair i had one time screen was bright white 100% when i took it aprt i found that it was a simple fix the lvds came disconnected so i rconected it and it fixed issue....so why in my case if the panel is getting no power from tcon via disconnecting calbes why isnt screen bright white 100% like it was on the right half when i disconnected right side and left the left side in?

[shelby5041]

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

fyi on my tcon there appears to be 2 lvds type cables going to it and it looks like one has traces going to one half of the chip on board and the other lvds leads to the other half of the chip and then when you look at the other side of chip going to the flat ribbon cables the traces are split in half just like below where the lvds cables connect...see my photo....does that mean anything.....

[shelby5041]

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

if i disconnect the lvds that goes to the right side of chip/screen and i unplug the right ribbon i get a picture on left side but kinda distorted like resolution messed up.....and i tried doing this with both ribbons plugged in but again i got no picture on entire screen when right ribbon is connected

[budm]

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

You can look up the spec sheet of the IC to see how it works.

[budm]

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

BTW, there are test points (copper pads) with VGH, VGL, VGH_M, VCC.
You can take the Voltage readings with all cables connected, and then with one ribbon cable going to the panel one at a time to see what Voltages you get.

[shelby5041]

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

ok thanks

can either one of you at least let me know if this cannot be a main issue in any way

if so then i will tear tv apart since im not going to repair a panel.....but if there is a chance it could be a main issue i will look inot repalcing main

[budm]

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

I myself never seen the main board causes this kind of symptom.

[shelby5041]

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

i see a vgh-m ..but id ont see any others...and its tiny....i se a bunch of v12 14 16 18 20 etc

and a couple of vcom

all are like tiny coper pads

[shelby5041]

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

ok if you have never seen it then thats good enough for me.....thank you

[budm]

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

They are around the top right area of the board just below VGH_M.

[shelby5041]

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

ok vgh-m without right cabe connected it 26v

[shelby5041]

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

ok i see them will check now without right connected

[budm]

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

What do you get with all cable connected? I think some of the Voltage will disappear when all cables connected due to shorts in the panel that kills the Voltages.

[shelby5041]

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

vgl 5v
vgh 27v
vgh-m 26v

without right ribbon connected