37lg7000 sound. No picture but backlight on.

[Rickig]

As above,
Any help would be greatly appreciated with diagnosing the problem board.

[Hamie]

Re: 37lg7000 sound. No picture but backlight on.

Pictures?

Include a picture of the t-con.

Check each end of the pico fuse on the t-con.
You should have 12v on each end.

[CapLeaker]

Re: 37lg7000 sound. No picture but backlight on.

If you have an oscilloscope, measure the LVDS out of the main board, while flicking the menu on and off.

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

No scope. I think tcon ok. Blue light comes on when set powered up. Think its main board of screen not sure.

[Hamie]

Re: 37lg7000 sound. No picture but backlight on.

Blue light doesn't mean the t-con is working.

Unplug half the tcon and see if you get an image on either side on the tv.

We need a photo of the tcon to see test points.

[CapLeaker]

Re: 37lg7000 sound. No picture but backlight on.

chances are 50/50.

[budm]

Re: 37lg7000 sound. No picture but backlight on.

blue light doesn't mean the t-con is working.

Unplug half the tcon and see if you get an image on either side on the tv.

We need a photo of the tcon to see test points.

+1.

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

If I unplug half the tcon I get half a white screen on the side I unplug

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

Tcon

[Hamie]

Re: 37lg7000 sound. No picture but backlight on.

Check voltages on t-con.

Vdd
Vcom
Vgl
Vgh

Post results.

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

Sorry.. Where exactly do I take the reading from?

[vinceroger69]

Re: 37lg7000 sound. No picture but backlight on.

if you look at the tcon where the top white connectors are for the ribbon cables just under there on each side there are the test points marked with a gold test point, put the black multi meter probe on the tv metal chassis and try not to let the probe slip and short anything out.

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

Vgl 2.5v
Think vcom_r 6.3v or 17mv (there's 2 test points under the vcom r writing not sure which is right)
Vcom_l is 12.6v
Vgh 12mv
Vcc 3.3v
Vdd 16.9v

[vinceroger69]

Re: 37lg7000 sound. No picture but backlight on.

i think the readings are meant to be took above the white line just to top left if that makes sence

[Hamie]

Re: 37lg7000 sound. No picture but backlight on.

Vcom is here:



Can you check vgl and vgh again as they are definitely not right.


Vdd is ok.

Vgl should give a negative reading. Ie -6v
Vgh should be about 15v

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

Vcom 6.9v

[Hamie]

Re: 37lg7000 sound. No picture but backlight on.

Vcom is fine.

[vinceroger69]

Re: 37lg7000 sound. No picture but backlight on.

did you see my post 14 you may need to check the readings again

[Rickig]

Re: 37lg7000 sound. No picture but backlight on.

Taking readings from here. The dot under each one and readings are as previously stated

[vinceroger69]

Re: 37lg7000 sound. No picture but backlight on.

possible i still think you need to check them above and too the left of the white line as if you count the numbers starting with a v theres just enough gold dots to match under the whie line but above there 4 test points whats hamie opinion?