JVC lt-42em73 Flashing Backlights

[JunkmanJimbo]

First I replaced the backlights. Then I found three bulging capacitors, one leaking, on the power supply board. Now, when I turn on the tv, the picture flashes with an image and then the picture goes away. I can unplug the tv and plug it back in, turn it on and the same thing happens. Please help. Thanks!

[dskall]

Re: JVC lt-42em73 Flashing Backlights

Do you still have backlights?

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

After the backlights are on and flashing for a short time, they go out. I can unplug the power cord and plug it back in and it will do the same thing.

[comptek]

Re: JVC lt-42em73 Flashing Backlights

Check your soldering work on the psu,
If it’s a vestel base unit check where the back lights plug in they’re called fingers just wet them with a tiny amount of solder and plug the strips back in hope this makes sense

[nomoresonys]

Re: JVC lt-42em73 Flashing Backlights

Did you test the new backlights before installation?

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

I checked the solder at the backlight plugs and they are fine. I disassembled the tv again and checked the backlights again. Removed everything down to the backlights, plugged in the tv and the backlights will flash once and go out. I tried another set of good backlights and they wouldn't even come on at all. So at this point I believe the problem is the power supply board. As I mentioned earlier, I replaced some bulging caps but apparently there's something else wrong with it. Sorry for the delay in responding but I haven't had the time to mess with the tv. Any ideas? Thanks in advance!

[diif]

Re: JVC lt-42em73 Flashing Backlights

You only replaced the visibly bulging caps ? There's a good chance more have failed and need replacing.

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

You're probably right. This board has vent capacitors with no value listed on them. How can I determine the value of these capacitors?

[diif]

Re: JVC lt-42em73 Flashing Backlights

How did you identify the bulging caps previously ?

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

The capacitors I replaced had the value printed on them. Only the vent caps don't have a value.

[diif]

Re: JVC lt-42em73 Flashing Backlights

Have you removed one and had a look all the way around ?

[nomoresonys]

Re: JVC lt-42em73 Flashing Backlights

get out the hairdryer and heat all those caps, then see if the tv stays on longer, if it does you can narrow down the culprit with more selective heating.

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

Will do. Thank you. I will let you know what happens.

[JunkmanJimbo]

Re: JVC lt-42em73 Flashing Backlights

get out the hairdryer and heat all those caps, then see if the tv stays on longer, if it does you can narrow down the culprit with more selective heating.

I actually found a power supply board at a good price. I received the board yesterday and that fixed the problem. Thank you to all of you for the help!

[nomoresonys]

Re: JVC lt-42em73 Flashing Backlights

glad to hear it,