What is the problem when i turn on and screen goes dark with ''failed to receive broadcast'' legend in middle of screen?

This tv have a problems with a board that call T-CON decodering board.This T-CON decodering board sit at the bottom in the middle of the LCD screen panel.This T-CON decodering board,decodering the tv incomming broadcasting tv signal before it go into the tv LCD screen panel to produce pictures.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish T-CON decodering board for the replacement.

Have you tested it with an external monitor?

I would say you either have a damaged inverter board or screen baclight lamp. Usually the inverter board fails in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

If the power totally fails (i.e. power is cut off, LEDs turn off, fans stop, ... etc), then this more likely to be because of a short circuit developing in a failing semiconductor component, or a power supply problem.
However, if the laptop is still running & only the display on its LCD is cut off but the laptop itself stays powered on, then your laptop might be experiencing a failing screen inverter board, a failing screen backlight lamp, or a failing LCD screen cable.

TYPICAL INVERTER FAILURE SYMPTOMS

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

That message is presented when a selected digital channel is too weak to decode. Let us hope that something was accidentally changed:

Is the channel legitimate?
Is the antenna/cable still connected (to the Digital input)?
Go into menu - setup - channel setup. Is the selection of either cable or air channels correct for your situation?
Use menu - setup - Antenna Setup-DIGITAL to examine the signal strength. Is there nothing at all, or is it just a question of strength?

Odds favor a change in channel setup that you would not have made intentionally, or a simple physical problem (input cable, etc.). Start from scratch, and check the settings and connections you originally made. Hopefully it will be simple and cheap!

Firmware needs to be upgraded on these units because the atellites are changing every so often so does the programming in these units, check to see if there is a firmware upgrade to fix these problems, the line in the middle of the screen is because it either hung during the process or the units lcd is going bad.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

Due to a new satellite launched this year, the WAAS is affected. Disable the WAAS, go to Garmin and download the latest software version FOR THIS UNIT. Install, enable WAAS and you should be good to go.

This is a battery save setting.
Check settings under Battery Saving Preferences, choose Never Turn Off Screen

A dark screen might be the result of a poorly adjusted display contrast. This can be altered by accessing the Setup menu and selecting Display.

When holding the power button, to turn on the device, the screen pixelates dark and then goes blank. If I continue to hold the power button the screen will continue to pixelate dark and then go blank. In the end, the device still will not turn on.

Hi

Have you gone under Preferences -> and disabling the auto keygaurd

there are 2 options

incoming calls received +

on a call

try disabling both these options and let me know what happens