Tomorrow I will try to dial down the power a bit and see if the invert xformers fizzle with a new fuse...

Thanks

On Tuesday, March 5, 2013 7:34:53 AM UTC-8, N_Cook wrote:
Sparkey wrote in message

...

Hi;



This is a Vizio M420NV.

Backlight was out, I found an open 3A fuse (TF1) on the main board that

carries 12.4 vdc. When fuse replaced, the backlight will flash a couple of

times and poof goes the fuse again.



I don't have a diagram. I wonder if this might be due to a inverter fault

?

I checked power transistors on main and power supply board.

Any ideas ?



Thanks,

I



Can you hear any fizzing/arcing across turns in the inverter Tx ?

Can you reduce the mains voltage a bit and maybe increase the amount of

on-time a bit , to monitor the fault situation a bit longer.