How can I go to the main menu without use the remote control to this tv?

You should have its remote control to select the main menu options. If you wish to buy its original remote control, contact the authorized service centre, or authorized dealer to your device brand.They can either give you a genuine remote control to your device, or can direct you, from where can you purchase a suitable one.
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It will be almost impossible to enter its menu option without its original remote control. If you wish to buy its original remote control, contact the authorized service centre, or authorized dealer to your device brand. They can either give you a genuine remote control to your device, or can direct you, from where can you purchase a suitable one. Gopakumar Gopalan Google

Thats the IR board. You can get the IR board along with the button assembly at the following link for your model its 15.00 just scroll down the page. It also may be the main board that has the issue if it is you can also get the main board there also its 84.00
http://tvrepairworld.com/lg__zenith_lcd__plasma_power_supply_boards

FPA locks the front buttons so children can not access programs without the remote. Use the remote to access the main menu then parental controls. On some models you might have to select special or chanell menu first. If FPA is on it will ask for a password. Turn off parental controls and all should work. This will require the original remote or a universal.

If the TV has a 'Menu" button on its front panel, you can enter its menu options, and can programme it. If there is no such button, you must have its remote control to programme it.

With Sony almost any Sony remote made for any of their regular sets and projection sets from 1985-2005 will work without programming for basic things---you may and are likely not to be able to use PIP and a few menu features---during that time Sony codes numbered less than 6 different types--the differences being mainly some features were not there.

Hello
If there isn't a button marked 'Menu' at the front panel of your TV, you can;t pull out Menu option without its remote control. No TV, which haven't Menu Button on its front panel, can't be controlled for all of its functions without its remote control OK.

Hello there,

For the Best Picture use the HDMI Cable and here are the Settings for the color setup.

Adjusting Your HDTV Settings
Using the On-screen Display (OSD)
The remote control or the control buttons on the side of the TV can control all the function settings. The
OSD allows you to adjust contrast, brightness and other settings. The TV will save changes made to the
settings, even if the TV is turned off.
The OSD consists of several menu options. The main menu options may vary depending on your
selected input source.
Note: Some of the main menu options may have additional submenus, for example, the TV Rating
submenu for Parental Controls.
The remote control or the buttons on the side of the TV can control all the function settings. The HDTV
Settings App allows you to adjust contrast, brightness and other settings. The TV will save changes made
to the settings, even if the TV is turned off.
The HDTV Settings App consists of several menu options. The main menu options may vary depending
on your selected input source.
Note: Some of the main menu options may have additional submenus, for example, the TV Rating
submenu for Parental Controls.
1. Press the VIA button.
2. Press ? or ? on the remote control to select the HDTV
Settings App, and then press OK. The Main Menu will be
shown on the screen.
3. Press ?, ?, ?, or ? on the remote control to select one of
the menu options:
? Input
? Wide
? CC
? Sleep Timer
? TV Settings
? PIP
? Network
? Bluetooth
? Help
4. Press OK to select the option or feature you want to adjust.
5. Once the menu option is displayed, press ? or ? on the
remote control to select one of the items to adjust.
6. Press OK to select it, and then press ?, ?, ?, or ? to adjust the selection.
7. Press BACK once to return to the previous screen. To return to your program once adjustments
have been completed, you can do one of the following:
a. Press EXIT on the remote control.
b. Press the RED button on the remote control.
c. Highlight and select the RED X in any menu.

i hope this was helpful don't forget to Rate

The menu button on the TV itself is bad and must be replaced ( or removed ). Alternatively the whole front button assembly can be disconnected. Just follow the wire back to the main chassis and unplug it.

The manual can be found near the bottom of the Product page for this TV.

From the manual, pg 11 -

If you misplaced your Remote Control you can still access most settings via the MAIN MENU screen when you press both CH UP (8) and DOWN (9) on the TV set. • Some features of your TV Set will not be accessible without the Remote Control. If you lost your Remote Control, contact a Sharp Authorized Servicer by calling 1-800-BE-SHARP for a replacement.

Let us know if this fixes it for you.