LG 37LC46 No backlight.

[Davy]

LG 37LC46 No back light, led goes to red after 5 seconds.

Looks as if the all in one psu and inverter board had their caps changed recently, with 'upped' voltage ratings, the main dc voltages appear to be correct and 'hash free'.

The back light control chip is a FAN7382, pin one has 15V Dc whilst it's mate has 19V on pin 8, the H out on pin 7 doesn't seem right, it looks like a row of spikes with smaller ones between, an identical waveform also appears on pin 8. The center of the push pull FET goes to the HV transformer primary then down to deck via a 1uF metalized film.

The top FET has the full rectified mains on the drain whilst the bottom FET has only about 14V on it's drain. No HV.... nuffin! I can only think of the 'Fan Chip'.

Anyone had problems with no back light in this LG brand of 'LC' telly's, am I missing anything or anything I should know about?

Dave