Panasonic LCD TV turns off after few seconds! HELP

[nomoresonys]

Re: Panasonic LCD TV turns off after few seconds! HELP

this could be a capacitor issue, they dont have to bulge to be bad, could also be a prob. with mainboard.

[kajaalyo]

Re: Panasonic LCD TV turns off after few seconds! HELP

Your first video, the picture looked brighter on the left side, that it is on the right side. Is that just on the video or really like that? Look at the voltages on the backlight driver board. There should be a few GND a few 24V, a BLON, a backlight adjust and may be an error line. For now check the 24V out and see if they disappear with the screen going blank.

My guess is that it disappears. However, you can test your backlight, by disconnecting all other boards from the power supply, force the power supply on and just run the backlight. See if it keeps running.

If you stand in front of the TV picture is darker on right side. BLON is pin that i need to short out to turn PSU on or i need to measure voltage from it, if so what should be the voltage?

If voltage disappears this is bad PSU than?
I will also try to test backlights like you tell me!

I will let you know about resoults!

Thank you.

[CapLeaker]

Re: Panasonic LCD TV turns off after few seconds! HELP

Your first video, the picture looked brighter on the left side, that it is on the right side. Is that just on the video or really like that? Look at the voltages on the backlight driver board. There should be a few GND a few 24V, a BLON, a backlight adjust and may be an error line. For now check the 24V out and see if they disappear with the screen going blank.

My guess is that it disappears. However, you can test your backlight, by disconnecting all other boards from the power supply, force the power supply on and just run the backlight. See if it keeps running.

[kajaalyo]

Re: Panasonic LCD TV turns off after few seconds! HELP

then I'd check power supply voltages, there should be a legend of expected voltages, right beside the pins where the connectors are.

Hy, i appreciate you help!
I will try to locate fuse on backlight board! Voltages are not marked on board, but i found them in service manual!
Do i need to look for voltage when disconected and powered on by shorting 2 contacts or do i need to look for voltage drop when tv turns off? Thanks

[nomoresonys]

Re: Panasonic LCD TV turns off after few seconds! HELP

then I'd check power supply voltages, there should be a legend of expected voltages, right beside the pins where the connectors are.

[nomoresonys]

Re: Panasonic LCD TV turns off after few seconds! HELP

cant see your backlight board very good, look it over real good, see if you can find a fuse to check.

[kajaalyo]

Re: Panasonic LCD TV turns off after few seconds! HELP

Hy, thanks for your help. I will try do that. I will let you know if i find anything.

Hy again i found only one fuse marked as f101 and its OK! Do you have any idea what this could be?

thanks

[kajaalyo]

Re: Panasonic LCD TV turns off after few seconds! HELP

be careful when working with power supply, HIGH VOLTAGE, on primary side, can be deadly, start with checking everything labeled F on the boards, F=fuse, look m over real goods, they can be really small.

Hy, thanks for your help. I will try do that. I will let you know if i find anything.

[nomoresonys]

Re: Panasonic LCD TV turns off after few seconds! HELP

be careful when working with power supply, HIGH VOLTAGE, on primary side, can be deadly, start with checking everything labeled F on the boards, F=fuse, look m over real goods, they can be really small.

[kajaalyo]

Hy,
I want to fix Panasonic VIERA tx-l32c10p LCD TV. But I cant find out wich part is bad. I recorded the video of whats happening, but I will describe the problem anyway.

1. When I turn tv on it turns on normaly, except the right side of display is darker than left side (this is not visible on the video).
2. Tv then turns off by itself after few seconds.
3. Red light starts blinking and it doesnt stop at all, except if I press any button on the remote (than it turns off and just blink i press any button on the remote).
4. In order to turn TV back on I have to turn it off and on with master power swich.

IF I QUICKLY PUT TV TO AV MODE (So there is no picture, except the AV sign) TV WONT SHUT OFF AND EVEN IF I OPEN MENU AND IT STILL WONT SHUT OFF. However if i plug in my digital converter TV will shut off after few seconds of showing picture

The video:

https://www.youtube.com/watch?v=NQlGGQWFCl8

There is a picture of tv with back cover off in attachments.



I tried to disconnect every single component one at a time to see if anything changes but no luck:
-Because right side off the screen is darker and silent buzzing sound is coming out of two boxes on backlight circuit board (No.0) I tought that there is a problem with backlight or backlight circuit board (No.0).
I disconnected 2 cables for backlights (No.1), but there was no difrience except display was not lighted.
Than I disconnected whole backlight circuit board (No.2), but there was no difrience again.
There is a blue LED on the backlight circuit board (No.3), there is a video of its activity!
There is a picture of backlight board (No.0) in attachements!



https://www.youtube.com/watch?v=rb3j4iCbRGs

I also tried to connect No.1 left connector to socket for right connector and No.1 right connector to socket for left connector to see if display will be darker on left side instead on right side, but there was no change.

I measured resistance of backlight (No.1) connectors and they are the same: 0,5 OHM!
I also measured resictance of No.1 sockets and they are also the same: 0,3 OHM!

-I tried to disconnect display board, speakers, board with buttons (i jumped the connector to turn tv on), LED and IR sensor board, but there is also no difrience.

-I ofcourse also put tv to factory settings.

I CANT FIND ANY BAD CAPACITORS, BAD CONTACTS, NOTHING FRIED UP OR ANY DAMAGE ON THE BOARDS AT ALL!!!

There is SELF TEST info in the attachments -I found default resoults in service manual and confirmed that they are the same.




I think that PSU is bad, but im not sure. What do you think?