LG 32LF580V - No picture but has sound

[donst]

Hi guys, hoping someone can help me with this problem. I have a LG32LF580V, the tv powers on but has no picture, when holding a torch close to the screen in a dark room the picture is then visible.

My initial suspicion was faulty backlights, but as i have no experience replacing LEDs and also knowing that replacing LEDs is a difficult procedure to undertake i decided to blindly buy a new power supply in the hope that this will solve the issue, it did not, i had exactly the same problem with the new power supply. So here i am, looking for help, any ideas on what the issue could be? In this type of situation can it only be the backlight? Or could it be a mainboard or tcon problem?

Pictures attached.

All help would be much appreciated, thanks in advance.

[handsworth]

Re: LG 32LF580V - No picture but has sound

I would suggest the backlights if you can see the image thru the black screen. Tv is working, just no lights. Typical LG

[donst]

Re: LG 32LF580V - No picture but has sound

I would suggest the backlights if you can see the image thru the black screen. Tv is working, just no lights. Typical LG

If it is the backlights, do all the strips have to be replaced or just the strips that have faulty LEDs?

[neilc6]

Re: LG 32LF580V - No picture but has sound

Just replace all of them. This model uses the thick lens which pop off easily. A 32 inch tv is fairly manageable and lower risk of cracking the screen. Probably an open led in the string. New replacement strips only $20 on ebay. Search youtube for videos.

[donst]

Re: LG 32LF580V - No picture but has sound

Hi neil, thanks for the reply. Must all the LEDs be replaced or can i replace just a single strip? I'd rather cut down on costs if possible and i'm finding that the single LED strips are significantly cheaper.

Also, can i just confirm, is it definitely the backlights? Is there no other reason why this would be happening? Faulty mainboard or t-con?

Thanks again for the replies guys, very much appreciated!

[neilc6]

Re: LG 32LF580V - No picture but has sound

$20 for a set of 3 new strips on ebay. Find the part number on shopjimmy and search on ebay. 90% of no backlight issues are the backlight. Since you already replaced the power supply,, that percentage is higher. If you had an led tester, you can cofirm the backlights are bad. You can also monitor the voltages going to the strips using a mutimeter when turning on the tv and see if they max out or settle.

[nomoresonys]

Re: LG 32LF580V - No picture but has sound

Do you have a multimeter and do you want to do some basic testing?

[donst]

Re: LG 32LF580V - No picture but has sound

$20 for a set of 3 new strips on ebay. Find the part number on shopjimmy and search on ebay. 90% of no backlight issues are the backlight. Since you already replaced the power supply,, that percentage is higher. If you had an led tester, you can cofirm the backlights are bad. You can also monitor the voltages going to the strips using a mutimeter when turning on the tv and see if they max out or settle.

Thanks, i'll probably end up buying the set of 3 but we'll see how things pan out first. An led tester is definitely something i should consider buying also, would have made things a whole lot easier here. Thanks again.

Do you have a multimeter and do you want to do some basic testing?

Sure, although please bare in mind i have very little experience with all this. My dad will help out as he used to fix tvs but he is retired now and the tvs he fixed were the old crt tvs, he pretty much has no experience in fixing flat screen tvs either.

Below are the multimeters that we have available to us, will they do?

[nomoresonys]

Re: LG 32LF580V - No picture but has sound

Sure, do test in number 3 below number 2 is a video example of testing, try to do the test just as instructed, see the little legend/map there by the 2 capacitors? report results as in pin name-pin-number and expected voltages and the voltages that you get while testing, both in standby and after you hit power on, this test is on the cold side, as always BE VERY CAREFUL when working with the powerboard there are DEADLY VOLTAGES on the HOT side.

[donst]

Re: LG 32LF580V - No picture but has sound

Thanks, i won't be able to test for a little while but once i have the results i'll let you know.

Thanks again!

Edit: One last thing, where should the meter be set? 200m DCV?

[nomoresonys]

Re: LG 32LF580V - No picture but has sound

20 vdc.

[donst]

Re: LG 32LF580V - No picture but has sound

With the yellow meter on the right i can't seem to find 'vdc', is vdc the same as dcv?

[nomoresonys]

Re: LG 32LF580V - No picture but has sound

Yes.