I got this one in today, the backlights come on for second (it shows 'PLEASE WAIT'), the go black. Check the 24V, BL_ENA are OK.
Check the fuse on the inverter, ESR of the caps on the inverter are OK.
Check the DCR of the inverter transformer high voltage windings side, all around 600 Ohms (they are within 1% from each other).
So thought I may have bad lamp.
I grab CCFL and solder a small solid wire to the center of the lamp base.
I touch one pin of the four pin (the inverter high voltage transformer has 4 pins on the high voltage winding side) at a time then turn on the TV to see how my CCFL will light up. I see that the CCFL is lit up partly on one of the winding. The good winding will light the lamp brightly. I remove the transformer, and sure enough, it has burnt winding.
So this is a new trick for finding bad inverter transformer.
Check the fuse on the inverter, ESR of the caps on the inverter are OK.
Check the DCR of the inverter transformer high voltage windings side, all around 600 Ohms (they are within 1% from each other).
So thought I may have bad lamp.
I grab CCFL and solder a small solid wire to the center of the lamp base.
I touch one pin of the four pin (the inverter high voltage transformer has 4 pins on the high voltage winding side) at a time then turn on the TV to see how my CCFL will light up. I see that the CCFL is lit up partly on one of the winding. The good winding will light the lamp brightly. I remove the transformer, and sure enough, it has burnt winding.
So this is a new trick for finding bad inverter transformer.
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