Sharp LC-42LB150U no power after lightning strike

[vanpye00]

Hi all,

I'm hoping someone with experience help me out here. I have a 42" LED Sharp TV, model's LC-42LB150U that stops working after a lightning strike. No standby led when plugged in, and doesn't respond to remote or tv buttons.

Here are what I've found:
- All fuses on the power board are ok.
- Diodes on the power board checked out ok in circuit.
- The caps on the power board seems fine (visually).
- With the main board disconnected from the power board, the voltages on the connector that connect the power board to the main board are:
ON/OFF = 0V
DIM = 0V
12V+ = 12.3V
GND = 0V
24VA = 0V
5.5V = 0V
- With the main board connected, the voltages of the same connector are:
ON/OFF = 2.5V
DIM = 0V
12V+ = 12.5V
GND = 0V
24VA = 25.2V
5.5V = 0V
- The power button works. When I press it, I can see the PWR pin on the mainboard changes from pulsed 3V to .1V. However, the ON/OFF pin on the power board doesn't change state when the power button is pressed.
- There is no power going into the "R", "G" pin on the mainboard so that's why there is no LED light.
- The mainboard pcb has multiple layers so I couldn't really trace where things are going. I couldn't find a schematic for it either.
- I think the problem is with the main board.

If anyone has any idea or could provide me with schematic/service manual for the main board, it would be really great! I've attached the images and a schematic for the powerboard.

[vanpye00]

Re: Sharp LC-42LB150U no power after lightning strike

Never mind, I figured out. The ic under the metal shield on the main board is bad. I couldn't find a replacement chip for it. I guess I just have to order a new board.