LG 42LE4500 No display

[tom66]

Re: LG 42LE4500 No display

The voltages, from the main board, should be both 3.3V, or so, as they are. But the LED backlight is not coming on, so something is wrong with the power board. Due to how these sets work, a single LED failure can't cause the whole panel to fail to light.

[dave bro]

Re: LG 42LE4500 No display

Ok, thanks. Is it possible to get a pdf of the service manual for this tv to maybe narrow the fault down?
Also, in your opinion considering the age of the tv, is a replacement a better option or a repair?
Thanks you for your help so far.

[tom66]

Re: LG 42LE4500 No display

Schematics are not available, and I can't see the power board clearly. You can try to repair it yourself by tracing circuits out and replacing parts. Or you can replace the board. I don't think either will be better than the other, except a component level repair will be much cheaper.

[dave bro]

Re: LG 42LE4500 No display

Any idea what circuit to start with or the most likely problem circuit?
Would it help if I tried to post a better picture of the power board?

[tom66]

Re: LG 42LE4500 No display

Try checking diodes, fuses, MOSFETs etc. I don't have enough time to trace a circuit out, so you can only really try the obvious.

[thuss]

Re: LG 42LE4500 No display

Hi

I have the same tv (42LE4500) which does the same thing.

I have checked the power supply with the screen working and I get a reading for the pwr 3.33 and Dvr as 12.

When the screen goes black with the sound still working I get the same readings i. pwr 3.33 and dvr as 12. Should my pwr be 20v? Is my power supply faulty?

Thanks in advance

[tom66]

Re: LG 42LE4500 No display

Why do you think PWR should be 20V?

[thuss]

Re: LG 42LE4500 No display

Hi

I thought looking at the power supply picture next to pwr on (which is in a box) it states 20V?

[tom66]

Re: LG 42LE4500 No display

Probably means the output above or below it is supposed to be 20V, normally PWR (meaning POWER ON) is >2V for on, <0.5V for off.

[thuss]

Re: LG 42LE4500 No display

ok thanks

[thuss]

Re: LG 42LE4500 No display

Hi

Has anyone repaired a 42le4500 power supply?

[thuss]

Re: LG 42LE4500 No display

Hi

Ive just realised that if I shine a bright light on the 42le4500 whilst in a dark room, I can see the image on the screen. So I assume that the back lights are not working.

Has anyone come across this and cured it with a power suppy board change?

[scooter13uk]

Re: LG 42LE4500 No display

Hi,

I know this an old post, but did anyone manage to get a fix for TV? Have same problem.

Scott.

[scooter13uk]

Re: LG 42LE4500 No display

Manual - http://servicemanuals.pro/serviceman...inish.html?m=0

[Maddoga1]

Re: LG 42LE4500 No display

LG 42LE4500 Keeps restarting with a click from the main board

My one works fine but turns it self off after about 5 mins and restarts over again and the keep restarting . Does anyone now that I should check first based on this fault

[newtothis]

Re: LG 42LE4500 No display

Voltages from PSU?

[Honacloi]

Re: LG 42LE4500 No display

Has anyone ever fixed this problem? Was it the PSU?

I have a 42LE4500 that now has a black screen with sound.

In a traditional LCD TV I would just replace the inverter but this set doesn't appear to have one. So does the PSU also act as the inverter in this case?

[tom66]

Re: LG 42LE4500 No display

I've had water damage kill a 37LE4500, the T-con was shorted due to shorted LCD panel.

[Honacloi]

Re: LG 42LE4500 No display

Erm... Thanks Tom. Alas I'm a little puzzled what that has to do with my question. It wasn't caused by water damage.

[newtothis]

Re: LG 42LE4500 No display

The PSU has the LED driver built in, Its that little green board attached to the PSU.

The PSU's in these sets are prone to failure and are not easy to repair and costly to replace... I have had a few LE models come to me in the last 18 months.

Let me guess... The LG logo comes up then goes off and loses backlighting?... still have an image via flashlight test? If so yes PSU