It's a big screen tv and it say locked

text was turned On I suspect.

Most TVs have a parental control lock that can be set to prevent children from watching specific television shows. In order to activate or deactivate the controls, you need to know the four digit security code or parental lock control password. If you forget the number you chose or if the lock gets set accidentally, it is still possible to unlock the TV.
Instructions

Turn on the TV and grab the remote. In most cases, you will need the original remote to unlock the TV if you aren't sure of the unlock code. If you don't have the original remote, you will need to purchase one.

Look at the screen. If you see a blank screen with a red key on the bottom of the screen, press 'Function' and 'Mute' at the same time. This should unlock the channel. This is an option for people who want the TV to stay locked but, want to be able to bypass the lock to watch a certain show or channel. All other channels will remain locked and the TV will fully lock when it is turned off.

Unlock all of the channels on the TV by entering the factory reset code. There are three main reset codes that TV manufacturers set. These are 0711, 6688 and 3308. Try each one until you find the one that works. This will reset the TV to original factory settings. When you do this, you will loose any information that you have stored in the TV, such as favorite channels, automatic timers and the clock. You will have to go through the full initial set up.

Call the technical support service number in your owner's manual if none of those codes work. A technician can help you troubleshoot the television because the problem may not be the locking control. When you call, make sure that you have the model number and serial number of the TV.

Take your television to a TV repair shop. In some cases, a professional who access to wiring diagrams for your television set may have to rewire certain components in order for the television to unlock. This is usually the case when the TV locks by itself while it is on.

Dear Sir:
Follow this step:
Turn on the TV and grab the remote. In most cases, you will need the original remote to unlock the TV if you aren't sure of the unlock code. If you don't have the original remote, you will need to purchase one.

2 Look at the screen. If you see a blank screen with a red key on the bottom of the screen, press 'Function' and 'Mute' at the same time. This should unlock the channel. This is an option for people who want the TV to stay locked but, want to be able to bypass the lock to watch a certain show or channel. All other channels will remain locked and the TV will fully lock when it is turned off.

God bless you

Turn on the TV and grab the remote. In most cases, you will need the original remote to unlock the TV if you aren't sure of the unlock code. If you don't have the original remote, you will need to purchase one.

Look at the screen. If you see a blank screen with a red key on the bottom of the screen, press 'Function' and 'Mute' at the same time. This should unlock the channel. This is an option for people who want the TV to stay locked but, want to be able to bypass the lock to watch a certain show or channel. All other channels will remain locked and the TV will fully lock when it is turned off.

Unlock all of the channels on the TV by entering the factory reset code. There are three main reset codes that TV manufacturers set. These are 0711, 6688 and 3308. Try each one until you find the one that works. This will reset the TV to original factory settings. When you do this, you will loose any information that you have stored in the TV, such as favorite channels, automatic timers and the clock. You will have to go through the full initial set up.

Call the technical support service number in your owner's manual if none of those codes work. A technician can help you troubleshoot the television because the problem may not be the locking control. When you call, make sure that you have the model number and serial number of the TV.
Take your television to a TV repair shop. In some cases, a professional who access to wiring diagrams for your television set may have to rewire certain components in order for the television to unlock. This is usually the case when the TV locks by itself while it is on

Try going into picture setting and reduce the zoom angle or if it's whilst you are watching Sky TV go into System Settings, Picture Settings and change the Aspect Ratio (ie. From 4:3 to 16:9 or visa versa)

Gadget

Hello
I've no details about this TV with me now. Sorry.

Hello
When an Insignia TV is locked, it keeps you from watching all of your channels by only displaying a black screen. Insignia TVs are locked from a single button command on the remote control, so it is easy for you to lock the TV by accident. Since Insignia TVs can be locked so easily, it's important to know how to undo this command and unlock the TV yourself. So, unlock your Insignia TV with the push of a button and once again enjoy watching your favorite programs.
· Find the lock button on the Insignia remote control. The lock button is located on the third column from the left on the second row from the top of the remote.

·Stand within operating range of the Insignia TV, then aim the remote at the TV's receiver and press the "Lock" button on the remote control.
· Aim the remote at the TV and press the channel buttons to make sure the TV is unlocked. When the TV is locked, it shows a black screen and does not allow you to view anything else. If the screen remains black, press the "Lock" button again. If this doesn't work, change the batteries in the remote and start over at step
OK

Hello
I thinks that you have its original remote handset with you now, and posts this solution. If you don't have it, either buy a new original remote handset or try to get it from any of your friends and relatives, who owns the same model of Mitsubishi Tv, you have now; only to unlock it. After unlock, you can use any other remote control.
Mitsubishi sets use a four-digit code for a V-Chip locked program, view a locked TV, cancel the lock, or to enter the V-Chip lock menus. You can view the locked shows on the TV set by pressing the number 9 and QV buttons on the remote at the same time, whenever your code is requested. This process temporarily unlocks the TV and asks you to enter a new code.
OK.

Hello,

Turn on the TV and grab the remote. In most cases, you will need the original remote to unlock the TV if you aren't sure of the unlock code. If you don't have the original remote, you will need to purchase one.
2
Look at the screen. If you see a blank screen with a red key on the bottom of the screen, press 'Function' and 'Mute' at the same time. This should unlock the channel. This is an option for people who want the TV to stay locked but, want to be able to bypass the lock to watch a certain show or channel. All other channels will remain locked and the TV will fully lock when it is turned off.
3
Unlock all of the channels on the TV by entering the factory reset code. There are three main reset codes that TV manufacturers set. These are 0711, 6688 and 3308. Try each one until you find the one that works. This will reset the TV to original factory settings. When you do this, you will loose any information that you have stored in the TV, such as favorite channels, automatic timers and the clock. You will have to go through the full initial set up.
4
Call the technical support service number in your owner's manual if none of those codes work. A technician can help you troubleshoot the television because the problem may not be the locking control. When you call, make sure that you have the model number and serial number of the TV.
5
Take your television to a TV repair shop. In some cases, a professional who access to wiring diagrams for your television set may have to rewire certain components in order for the television to unlock. This is usually the case when the TV locks by itself while it is on.

Also note that forgotten the passcode of your Mitsubishi TV. You can make it alive without knowing the passcode. Please follow
V_Chip lock bypassing prodedure is as follows
You can view your locked TV, cancel the lock, or enter the V_chip lock menus.

This is done by pressing the number "9" and "QV" buttons on the remote TV control at the same time, when your passcode is requested. This process temporarily unlocks the TV.
When entering the V_Chip lock menu, this process deletes your old passcode and prompts you to enter a new passcode.


I hope this will help to solve the problem...

its no big problem.I implore you visit the user's manual to see how to zoom and undo it. Get back if you encounter further problems.