Display “Locked” in LCD/CRT
The moment power on, the screen will display “LOCKED”, i don’t know how to reset to remove the screen lock.
You need the service manual to find out the combination keys to unlock it. You can also try some of the main button in the remote control like pressing menu/ok for more than 30 seconds to unlock it. If the set is a LCD Monitor, try pressing the menu button for more than 30 seconds to unlock it.
Sometimes no method what method you have used the display “Locked” would still appear the moment you turn on the set. In this case, it can be due to stuck button in the front control panel. In some other cases it could be due to bad EEprom/Flash Rom /MCU IC programs. In this case a programmer and original program is a must to solve the problem.
I came across a similar symptom and the problem was due to lower than normal voltage to the EEprom IC. The supply to EEprom IC should be 5 volt but the voltage measured was only 2 to 3 volt. The solution was to replace the 5 volt regulator IC. After that one has to press the menu again for 30 seconds to unlock it.
If you did not press on the menu button, the “Locked” display would still remain even though you have already replaced the voltage regulator IC. Please take note on this.