Display not working, power button LED turns on blue for 1 second and won't turn on again

Hi Tania,
Have you gone through this checking sequence.? it's from a Panasonic a/c manual. It could be something as simple as a clogged filter. Once you have rectified the fault, you will probably have to clear the fault code as described at bottom below, before it will condescend to work again.
David

• Once error occurred during operation, the unit will stop its operation, and Timer LED blinks.
• Although Timer LED goes off when power supply is turned off, if the unit is operated under a breakdown condition, the LED will ON again.
• In operation after breakdown repair, the Timer LED will not blink. The last error code (abnormality) will be stored
  in IC memory.

14.2.2 To Make a Diagnosis

1. 1 Timer LED starts to blink and the unit automatically stops the operation.
2. 2 Press the CHECK button on the remote control continuously for 5 seconds.
3. 3 "- -" will be displayed on the remote control display.
   Note: Display only for "- -" (No signal transmission, no receiving sound and no Power LED blinking)
4. 4 Press the TIMER ? or ? button on the remote control. The code "H00" (no abnormality) will be displayed and signal will be transmit to the main unit.
5. 5 Each press of the button (? or ?) will increase error code number and transmit error code signal to the main unit.
6. 6 When the latest abnormality code on the main unit and code
   transmitted from the remote control are matched, Power LED will
   light up for 30 seconds and a "beep" sound (continuously for 4
   seconds) will be heard. If no codes are matched, Power LED will light up for 0.5 seconds and no sound will be heard.
7. 7 The breakdown diagnosis mode will be canceled unless pressing the CHECK button continuously for 5 seconds or operating the unit for 30 seconds.
8. 8 The LED will be off if the unit is turned off or the RESET button on the main unit is pressed.

14.2.3 To Display Memorized Error Code (Protective Operation)

1. 1 Turn power on.
2. 2 Press the CHECK button on the remote control
3. 3 "- -" will be displayed on the remote control display. Note: Display only for "- -" (No signal transmission, no receiving sound and no Power LED blinking)
4. 4 Press the TIMER ? or ? button on the remote control. The code "H00" (no abnormality) will be displayed
   and signal will be transmit to the main unit.
5. 5 Each press of the button (? or ?) will increase error code number and transmit error code signal to the main
   unit.
6. 6 When the latest abnormality code on the main unit and code transmitted from the remote control are matched,
   Power LED will light up for 30 seconds and a "beep" sound (continuously for 4 seconds) will be heard. If no
   codes are matched, Power LED will light up for 0.5 seconds and no sound will be heard.
7. 7 The breakdown diagnosis mode will be canceled unless pressing the CHECK button continuously for 5
   seconds or operating the unit for 30 seconds.
8. 8 The same diagnosis can be repeated by turning power on again.

14.2.4 To Clear Memorized Error Code after Repair (Protective Operation)

1. 1 Turn power on (in standby condition).
2. 2 Press the AUTO button for 5 seconds (a "beep" sound is heard) on the main unit to operate the unit at Forced Cooling Operation Mode.
3. 3 Press the CHECK button on the remote control for about 1 second with a pointed object to transmit signal to
   main unit. A "beep" sound is heard, and the Error Code is cleared

Repair work to Plasma TVs are skilled one. It will be best to contact any service technician in this case.
It sounds that the main power regulator board to your Plasma display is faulty.
Eventhough you are able to buy and replace a power regulator bord to this set, there are some voltage adjustments have to be done; and it is a must. you should have all testing instruments, and ability to follow its circuit diagram, and have to find out the voltages set adjuster points.
If you are confident, just proceed. Otherwise, contact either a service technician, or the authorized service center for LG
If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. Do a search by type in the brand name of your device at its search box and press "Enter".
http://electronicshelponline.blogspot.com/

Contact hp servis

Before going OFF, the standby LED might blink. These blinks are fault indication. The number of blink should be counted. Count the number of blinks at one time, before the TV goes OFF. [eg: 4 blinks Power SOS P Board; 6 blinks Driver SOS 1 SU / SD / SC Boards
(SC energy recovery circuit)] and so on. you can get more details from this site named 'Electro-help'. You can reach it by searching the keyword "electronicshelponline" by internet.

That would leave the processor ic, usually most motherboards do not include that.

I also had blown capacitors on my power supply. You can see when they're bad: the tops split or bubble up like a dome. I changed most of the caps, just to be sure, and it fixed the problem. Careful of the larger capacitors. They stay powered for some time and can shock you pretty badly. Good Luck

The following steps should be able to correct the problem:
1) Unplug the TV or remove AC power from the TV
2) Count to ten and then plug in the TV
3) Locate the [Menu], [VOL-] and [Power] button on the TV’s side panel
4) Using the buttons on the TV’s Side Panel, press and hold both the [Menu] and [VOL-] buttons.
5) While holding those buttons, press and release the [Power] button one time and count to 3 before releasing the [Menu] and [VOL-] buttons.
6) The TV’s lower left Blue Power LED will come ON.
7) Wait 30 seconds. Confirm that the blue LED on the Lower Left of the TV (not the iPod dock for iPod models) has remained ON during this time.
8) Press the [Mute] button on the TV remote twice
9) Unplug the TV or remove AC power
10) Count to ten and plug the TV in
11) The TV power should automatically come ON and the blue power LED with be ON
12) Wait 40 seconds and the TV picture should appear
13) You can now continue using your TV.
14) If the picture does not appear, power on the TV manually:
· If the LED begins flashing, unplug and power ON a second time.
· If the LED begins flashing again, power ON the TV without unplugging
If the LED begins flashing again, contact us directly by phone to obtain a local authorized service center for you.
If the TV does power on, please reply back with the software version number for us to research this issue. Please follow these steps to obtain the software version number:

1) Press the [Menu] button on the remote control.
2) Using the arrow keys in the center of the remote, scroll over to the "settings" menu and select the [OK] button on the remote
3) Scroll down to "system info" and select [OK] button on the remote

For clarification of code/blinks significance you should check at mfg web site .

The following procedure will re-establish the communication link between the Headphones and the Wireless adapter, this is called "pairing". Before you start please make sure both the headphones and the wireless adapter are fully charged and turned off.
Note: The headphones and the wireless adapter come pre-paired from the factory.
1. Press and hold the power button on the headphones. See Figure 1.

Figure 1

2. Continue to hold the button down until the LED starts flashing red/blue in an alternating pattern. Release the button when the LED starts flashing red/blue. See Figure 2.

Figure 2
3. Once the headphones LED is flashing red/blue, press and hold the power button on the wireless adapter. See Figure 3.

Figure 3
4. Hold down the button until the LED starts flashing red/blue in an alternating patter. The LED will blink blue, then turn off for a few seconds then blink red/blue. Release the button when the LED starts flashing red/blue. See Figure 4.

Figure 4
5. Once both the headphones LED and the adapter LED is blinking red/blue, press the volume up button once on the headphones. See Figure 5.

Figure 5
Once the headphones is paired with the adapter, the LED on the headphones will blink blue once every two seconds. See Figure 6.

Figure 6
When the adapter is paired the LED will be solid blue. See Figure 7.

Figure 7
The adapter may continue to blink red/blue for a few seconds even after the headphones LED starting blinking blue. This is normal; the adapter may take a few additional seconds before the LED turn solid blue.
Once the headphones and the adapter are paired, it is not necessary to pair them again even if the batteries on both units are completely drained.
Additional Note: Repeated pairing will not improve the sound quality or give the headphones and the adapter a cleaner connection.

Programming the Remote Control Remote-control switchover Press VCR/DVD, SAT/CABLE or AUX to select the device you want to control. To program the remote control Press and hold VCR.DVD, SAT/CABLE or AUX for over 2 seconds until the LED on the remote control turns off. Release the button the LED will light again (the remote control enters the PROGRAMMING mode). Enter three-digit code number for your equipment. If the correct code number is entered, the LED blinks three times. If you enter a code not listed below, or you press any other buttons than SEARCH and 100+, the LED turns off. To search codes Press ad hold VCR/DVD,SAT/CABLE or AUX for over 2 seconds unil the LED turns off. Release the button (the LED wil light again) and the remote control enters the PROGRAMMING mode. Press SEARCH. Press CH+/- to search codes downwards or upwards. Each time you press CH+/-, the code number decreases or increases by 1 while the remote control sends the code number for POWER button on your device. If the desired code number is found,press 100+ to program the code for your device until the LED blinks three times.Then the remote control exits from the PROGRAMMING mode and returns to norml operation. Or press any other button to exit from the PROGRAMMING mode after the LED blinks rapidly eight times, and the operation is not active. To check the current code number Press and hold VCR/DVD, SAT/CABLE or AUX for over 2 seconds until the LED turns off. Release the button (the LED will light again) and the remote control enters the PROGRAMMING mode. Press 100+ . You may read the code numder according to the LED display status as follows. * If there is no operation within 20 seconds during the steps mentioned above, the remote control will automatically exit from the appropriate operation. Code Number First - digit 0 1 0 1 Second - digit 0 0 4 5 Third - digit 0 6 3 0 First - digit Blinks rapidly once Blinks once Blinks rapidly once Bliks once Secod - digit Blinks rapidly once Blinks rapidly once Blinks four times Bliks five times Third - digit Blinks rapidly once Blinks six times Blinks three times Bliks rapidly once