LG 47LF66 - Backlight on then off!

[LJBrzozka]

I have an LG 47LF66 TV with a problem

The symptoms are:

When you turn the TV on, sometimes everything works well
If you then turn it off and back on again, the picture does not come back. Instead you get a flash of coloured vertical lines and then nothing (sometimes a picture that looks like interference)

Now, the TV wont come back on at all. The backlight flashes on for a split second and then goes off. Sometimes, unplugging for a while and then reseating the connectors will make the TV work again but then it just goes back to the problem loop above


Has anyone experienced this problem? I have tried replacing the TCON board which hasnt made a difference. The power board all looks good (no blown caps or obvious blown components).

The TV works fine as long as it stays turned on. The issue only arises when its turned off and then back on!

Any suggestions gratefully received!

[CapLeaker]

Re: LG 47LF66 - Backlight on then off!

Check the LVDS signal from the main board when the fault occurs with an oscilloscope and turn the menu on/off all the time and see if the signal changes. Check the PSon and the BLon signal from the main board to the PSU too. Then you know the condition of your main board. Also you might have to check the backlight inverter. Hope that helps.