Turns off about 2 seconds after turning on

Fault in the main power supply regulator board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/

So you need to be In the main menu interface then press the power button for about 5 seconds to shut it down. Below is the power section out of the manual.


1.2 POWER
startup: Long Press and hold the power button, the system will enter the main interface
shutdown: In the main menu interface, Press the power button about 5 second to shutdown, The system can hint "power off" option, Clike"ok". you can safely shut down.
Lock screen: Short press Power button to lock screen or unlock screen.
Remark 1.When power is empty,system will shut down automatically.
2.Illegal turn off the device,restart will scan and restore the disk,it may take longer time to enter into system

Most sets will shut down very fast if no signal at all.

If you can before it shuts off try to change input to one of the rear audio video inputs that has something connected to it and turned on.

Failing there and if using a box of some type for signal--unplug it and the set both for a while---plug back both and let each try to boot up.

A total loss of signal or a glitch with the set or a box can confuse the TV set's Microprocessor.

will it show a picture before it shuts down?

you have to turn the screen control up a bit.there are 2 conrols on the flyback transformer,top one is focas bottom one is screen,turn it up 1/8 turn turn set off then on.repeat this until picture appears(if you turn it up too much picture will be to brite with lines and will shut off) if it shuts off just turn contron down a bit then restart it.

E940 - Main Switch Error

The detection mechanism is as follows:
· The machine reaches the auto-off time.
· The solenoid mounted inside the main switch turns on for 3 seconds.
· If the main switch does not turn off, the solenoid is turned off for 1
seconds.
· The solenoid is once again turned on for 3 seconds.
· If the main switch does not turn off at this point, the solenoid turns off
and E940 lights.
Possible Causes -
The main switch is defective.
The main control board is defective.
1. Turn on the main switch.
2. Enter SP5-810 (SC code reset) and press the Enter key.
3. Exit SP mode and turn the main switch off and on.

Reagrding unlock of samsun ht-x715.

Found this
http://www.amazon.com/review/R2FMHKVOZYF6HX/ref=cm_cd_NOREF?%5Fencoding=UTF8&cdPage=&cdERR=noPurchase#CustomerDiscussionsPost


Worked for me with a small change

1. Remove disc from tray.
2. Switch off player and unplug from mains.
3. Wait 30 seconds, then reconnect mains.
4. Turn on player with remote. press the 'Repeat' on the remote for 10 sec'.
5. Press enter on remote. (There will be no on-screen response.)
6. Press 8, 4, 2, 6, 9 on the remote. (There will be no on-screen response.)
7. Press enter on the remote. Player will automatically shut off.
8. Turn player on.
9. Turn off.
10. Turn player on then off again.
11. Player is now region-free.

there is no region hack for.......
but please try the following code may be works>>

1. Remove disc from tray. 
2. Switch off player and unplug from mains. 
3. Wait 30 seconds, then reconnect mains. 
4. Turn on player with remote. Wait for player to finish loading and display 'no disc'. 
5. Press enter on remote. (There will be no on-screen response.) 
6. Press 8, 4, 2, 6, 9 on the remote. (There will be no on-screen response.) 
7. Press enter on the remote. Player will automatically shut off. 
8. Turn player on. 
9. Turn off. 
10. Turn player on then off again. 
11. Player is now region-free.

Thanks for using FixYa.

Problem solved! The main power thingy (the thing with the big red wire coming out of it) was all black and dusty. There was 'soot' all over the whole insides of the monitor. I concluded that this monitor should be laid to rest, and a new flat-screen monitor erected in its place.

1. Unit powers on and works properly for a while then shuts off with a red lamp LED (lamp error). Suspect bad lamp part # 915P020010 2. Lamp enable line at J14 pin 6 does not switch to 5 volts after turn on, 12 and 5 volt supplies are good. Suspect the Light Engine part # 939P977010 3. At power on the lamp turns on and off three times and then the unit shuts down with a red lamp LED (lamp error). Replace the Light Engine part # 939P977010 4. Check for 12-volts DC at J-9 connector pin 4 on the Engine Driver PCB, if missing check for an open F9A09 on the Power PCB, if it is open replace F9A09 part # 283P127060 and the Light Engine part # 939P977010 5. Lamp enable line at connector J14 pin 6 on the Engine Driver PCB switches to 5 volts after turn on but does not go back to 0-volts (low) after 5 seconds, 12 and 5 volt supplies are good. Suspect the Light Engine part # 939P977010 6. Check for 5-volts DC at J-9 connector pin 1 and 2 on the Engine Driver PCB if low or missing check C9A37 and C9A38 both 3300 UFD 10 V part # 181P732040 on the Power PCB part # 930B929001