Panasonic TX-L42E5B powering off

[alerton]

Hi again everyone, one of our other TV's has started having a problem so hope someone might be able to help me get it fixed.

its a Panasonic TX-L42E5B. it works fine for hours and hours then randomly goes off. when it goes off the red light flashes once every 2 / 3 seconds and then repeats endlessly. the remote will not operate it when the light is flashing. turning the tv off / on with the power button or unplugging from the wall and then powering it back on works. when it comes back on it then works again, sometimes for a few seconds and sometimes for hours and hours. ive checked the firmware version and its on the latest, done a factory reset but not done anything else yet. what would be anyone's advice please?

remember im not a tech expert just an enthusiastic amateur.

Thanks everyone.

[nomoresonys]

Re: Panasonic TX-L42E5B powering off

Try turning the backlights down NOT brightness, see if you notice any difference.

[alerton]

Re: Panasonic TX-L42E5B powering off

Try turning the backlights down NOT brightness, see if you notice any difference.

there is no backlight setting in the menu i looked for it earlier.

i did however notice that the lower half of the screen gets 'dim' just before it shuts down and when trying to restart it the lower half is 'dim' sometimes which is when it goes back off within seconds yet other times the lower half seems 'normal brightness' when first switched on, then it goes for hours and hours before the problem re-occurs.

[CapLeaker]

Re: Panasonic TX-L42E5B powering off

one of the backlight transformers getting hotter than the others?

[nomoresonys]

Re: Panasonic TX-L42E5B powering off

Guess it could be a bad solder joint somewhere?

[alerton]

Re: Panasonic TX-L42E5B powering off

one of the backlight transformers getting hotter than the others?

not sure, i didnt even take the back off the tv yet but a local guy here seems to think its an LG panel and hes 99% sure its going to be a led problem.

i cant find much info about this tv online, is there just 1 led bar or 1 each side (i know its side lit) i looked on ebay and i can only see listings for 1 side, they all seem to be right side which leads me to think there may only be 1 side lit?
also has anyone done the backlights on this tv before? is it as easy as the vestel (toshiba) set i have done before?

thanks for the help and advice again guys

[alerton]

Re: Panasonic TX-L42E5B powering off

OK well i bit the bullet and attacked it with a screwdriver

about 30 minutes and what seemed like 250 screws later im inside the screen.

just 1 led bar as i suspected and sure enough 1 led is off totally and about half the leds come on then go off almost instantly, they can be coaxed to stay on with a bit of tapping / pressure so im guessing theres a bad solder joint somewhere.

ebay to the rescue again and a new led strip ordered from China for about £17 pity it will take so long to arrive, im bound to have forgotten which screw goes where by the time its here lol

[alerton]

Re: Panasonic TX-L42E5B powering off

still waiting for my new led, will update when its here and fitted but in the meantime i found this online that might be of help to others (borrowed from an ebay listing for Model: TC-L42E50 which from what i can see is the american version of TX-L42E5B)...........

TIP FOR TROUBLESHOOTING.

Power LED Blinking timing chart
1. Subject: Information of LED Flashing timing chart.
2. Contents: When an abnormality has occurred the unit, the protection circuit operates and reset to the stand by mode. At this time, the defective block can be identified by the number of blinks of the Power LED on the front panel of the unit.

Blinking Times Contents Check point:
1 BACK LIGHT SOS: LCD PANEL, P-Board
3 Tuner SOS: A-Board, P-Board
4 P15V SOS: A-Board, P-Board
7 SUB 3.3V SOS: A-Board
9 SOUND SOS: A-Board, Speaker
10 ZWEI2 SOS: LCD PANEL
12 BE (sLD) SOS: A-Board
13 EMERGENCY SOS: A-Board

LCD Panel test mode
Purpose: To find the possible failure point where in LCD Panel or Printed Circuit Board when the abnormal picture is displayed.
How to Enter:
While pressing [VOLUME ( - )] button of the main unit, press [SUB MENU] button of the remote control three times within 2 seconds.
How to Exit: Disconnect AC plug from wall outlet.
How to confirm:
If the abnormal picture is displayed, go into LCD Panel test mode to display the several test patterns. And then, judge by the following method.
Still abnormal picture is displayed: The cause must be in LCD Panel.
Normal picture is displayed: The cause must be in A board.
Remarks:
The test pattern is created by the circuit in LCD Panel.
In LCD Panel test mode, this test pattern is displayed unaffected by signal processing for RF or input signal. If the normal picture is displayed, LCD Panel must be okay and the cause of failure must be in A board.

[alerton]

Re: Panasonic TX-L42E5B powering off

new led strip arrived and fitted and all seems to be working fine again. been on for a full day and half the night and no problems yet so fingers crossed

[nomoresonys]

Re: Panasonic TX-L42E5B powering off

Nice.