When I push the power button, the TV starts to boot up (for about 3 seconds) then shuts back off.

Hello;

Without knowing the codes for the specific brand names and models of your devices, this is how you program the Zenith MBR3447 for your TV, VCR, DVD Player, CD Player or Audio Receiver:

TV

1. Push the "Power" button on the TV to turn it on.
2. Press and hold the "PRG" button in the upper left corner of the remote. Release when the indicator light, located in the top center of the remote control, comes on.
3. Push the "TV" mode key located at the top of the remote.
4. Enter 0 -- 0 -- 0 on the remote's number pad, then press the "Enter" button.
5. Aim the remote control in the direction of the TV's IR sensor and push the "Power" button. Pause a second. If the TV fails to shut off, push the "Power" button again. Repeat until the TV does shut off. Each time the "Power" button is pressed the Zenith MBR3447 tries using a different TV device code from its code library to turn the TV off. Therefore, when the TV finally does shut off it's an indication that the remote is temporarily programmed with the correct device code to control the brand of TV you're using.
6. Press "Enter" to save the current code.

VCR

1. Push the "Power" button on the VCR to turn it on.
2. Press and hold the "PRG" button in the upper left corner of the remote. Release when the indicator light, located in the top center of the remote control, comes on.
3. Push the "VCR" mode key located at the top of the remote.
4. Enter 0 -- 0 -- 0 on the remote's number pad, then press the "Enter" button.
5. Aim the remote control in the direction of the VCR's IR sensor and push the "Power" button. Pause a second. If the VCR fails to shut off, push the "Power" button again. Repeat until the VCR does shut off. Then press "Enter."

DVD Player, CD Player or Audio Receiver

1. Push the "Power" button on the device your programming the remote to control to manually turn it on.
2. Press and hold the "PRG" button in the upper left corner of the remote. Release when the indicator light, located in the top center of the remote control, comes on.
3. Push the "AUX" mode key located at the top of the remote.
4. Enter 0 -- 0 -- 0 on the remote's number pad, then press the "Enter" button.
5. Aim the remote control in the direction of the device's IR sensor and push the "Power" button. Pause a second. If the device fails to shut off, push the "Power" button again. Repeat until the device does shut off. Then press "Enter."

I assume it is not shutting down. Do a complete reset, unplug computer from wall push power button in for 3-5 seconds, then plug it in and restart the machine. Then let it complete the boot up process then go to start and shut it down again see if it shuts down now. Thanks for the question hope this assists you. John

maybe is the hard disk malfunction

Have you tried attaching an external monitor when the LCD screen is disconnected from the motherboard? this connector is located under the keyboard strip – a piece of plastic just above the keyboard.
If it works, this way, then the video cable isn’t seated properly in the connector on the back of the screen. Plugging the video cable back in should fix the problem.
I don’t know how comfortable you are with taking apart laptops but I think that this information could be useful for you.
Source: http://www.asklaptopfreak.com/laptop-notebook-help/2006/08/08/laptop-powers-on-and-shuts-off-immediately/

I've had a similar situation with a Magellan, it would power off despite being plugged in.

Its usually a battery issue, perhaps its not getting enough power? You could try to unplug it and do a "hard battery reset" depending on the type of battery. Keep turning it on and let it run out, until it wont even turn on anymore, after that plug it into a charger while off and allow it to charge completely. Turn it on, see if it still shuts off.

Good luck!

More information would help to resolve this issue.

Are you shutting down by selecting Start and shutdown or have you tried pushing the power button on push (not holding the power button)?

Try this:
Press and hold the power button in solidly for about 10 seconds. If it shuts down before you get to 10 just let off the power button. This should work, but may not solve the problem.

If you reboot it and still can not shut down from Windows, hold power button until it shuts down, unplug the power cord and disconnect everything from the computer other than the keyboard, mouse and monitor. With the power plug still unplugged, hold the power button in for about 15 seconds (this resets the power supply and can clear a corrupt BIOS).

Reconnect power and after booting, see if you can shut down from Windows.

If still no go, click Start, Programs, Accessories, System tools and select System Restore.

Follow the prompts and select a bold date back to a time before you had problems shutting down. That should do the trick.

Let me know if you get it fixed or if you need more advice.

Honest1abe

Sounds like a hardware failure. Possilbly the motherboard, more than likely, the power supply.
But then - maybe neither.
Shut it off completely, once you restart, start hitting the F8 key ( once a second ) until you see the " Safe Mode" choices screen. Drop down and select the " Last known Good Configuration" option and hit enter.
If this doesnt work, try the same proceedures ( restart - F8 ) but this time select safe mode - at the top of the list.
If you sucessfully boot in safe mode, you have a system file problem that could be virus related, file table corruptions or registry problems or all combined.

We're here if you need us.
www.wvpcrepair.com

If it's not beeping during the first start up then it's not POSTing.  Beep means everything connected to it seems to be functional ie PnP  
Try pulling out your memory and reseating it.   Try pulling out your battery for 5 minutes then plug in ac(without batt) and see if it will boot.  Try pulling your hard drive and reseat.  (access by covers on bottom...dont be scared. Touch something that's grounded just before you remove) If all this and still no full POST(with beep/s) then sounds like a new mobo or processor.
James Mac

If it is the power LED that is flashing orange 2times every five seconds , it suggests that the Lamp Cover was not reinstalled correctly. Remove and reinstall it