Open side of fuse to fan ground is approx. 10.2M ohm.
If I measure 24VINV to ground I'm obviously charging some capacitors so the resistance is increasing with time. But it gets to over 1M very quickly.
Going with my troubleshooting skills:
I've got a blown fuse on my power supply that generates 24V and 12V.
The 24V goes to the backlight inverter and I don't know what else.
The 12V drives the fan and I don't know what else.
But no matter where these voltages go and what they supply the main processor only verifies they are present by the turning of the fan. So I would assume they are for functions not necessary for the operation of the processor.
Now I don't know why my fuse is blown. The power supply is a resonance mode switching design which makes troubleshooting difficult. If the load draws too much current, the transformer is damaged, the switching transistors or output rectifying diodes are damaged they all result in too much current draw at the primary side of the transformer.
From the fuse I can determine that this switching supply is somewhere in the 100 to 110W range (49V & 2.5A fuse). The items that I'm aware of that would require 24V or 12V and high current in an LCD TV are the backlighting & LCD panel IR heating. I would expect that both of these functions would be generated by the backlight inverter.
Switching power supplies can be very robust if designed properly. The same for the backlight inverter as it is also some sort of switching power supply I would assume.
Should I just replace both the backlight inerter and the power supply board and be done with it?