LG LN5700 logo flash then dark screen

[martino]

Re: LG LN5700 logo flash then dark screen

Don't throw it away! Remember,i got all the boards etc for this thing
Worst comes to worst I can make mine working good again(fixing the backlight) and sell ya everything for a sharp price. Think of the for ever fame and amazement you get from your family once you got it all fixed up!

[ReeceyBurger123]

Re: LG LN5700 logo flash then dark screen

Never give up !

[martino]

Re: LG LN5700 logo flash then dark screen

Never give up !

What's your take on this thing reeceyBurger?

[ReeceyBurger123]

Re: LG LN5700 logo flash then dark screen

My advice firstly stack repair that Led and factory reset the Tv.

[martino]

Re: LG LN5700 logo flash then dark screen

Agreed,the uneven measurement between the two groups and the reputation of this model,I repaired a lot of these and it's always the bloody backlight

[Alastair E]

Re: LG LN5700 logo flash then dark screen

Worth checking all the plugs/connectors to each strip--Ive had a few intermittent ones...

[robledjl]

Re: LG LN5700 logo flash then dark screen

This is the reason why I love forums...sharing the knowledge others have is great for us people that like to fix things for a hobby plus save some money... UPDATE: so I got ahold of a real fluke from my neighbor.. Did the same test again and one side reads 5.40 while the other says O.L!??? Did this test 3 times with the same results, all backlights turn on.

[robledjl]

Re: LG LN5700 logo flash then dark screen

Can anyone tell me what's the deal with my last multimeter reading? Should I check all diodes?

[martino]

Re: LG LN5700 logo flash then dark screen

was the multi meter set to auto? If backlight is on then meter can be on manual,you are not looking for a min max thing,that you use when you get backlight only for a split second before it errors out.
Set meter to like 600 volts DC on manual.. Then measure both sides again.
Also,Alastair E suggested flacky connectors on the led strips. Maybe while they are on wiggle the connectors a bit with a wooded spoon or something?

[robledjl]

Re: LG LN5700 logo flash then dark screen

Ok I still haven't given up yet, I had my truck Ive been working on but that's fixed so now I'm back to this. OK Martino if you are still around I just followed the suggestions from the last post... All connections are firm and not loose. I did check the voltage on manual and one side tested 105v as soon as the TV turned on and then dropped to 59 and was steady. The other side stayed around 25 to 35v the whole time, it didn't even hit 105v as the other side did. Any more suggestions?

[martino]

Re: LG LN5700 logo flash then dark screen

I had dropped this a bit as I kinda figured you had given up lol.
What was wrong with the truck? Could have helped with that
the drop from 105 to 59 is normal as it starts on full brightness and then goes to the backlight preset.. the 25 to 35 seems odd to me as the tv has 2 groups of leds,so you would think measurements should be the same.
I got one here where I sadly broke the screen from(picked up the panel to rough and it cracked,grrr.) but I have the whole thing still,so I will fire it up tonight and take some readings. What strips get messed with? there is L1 and L2 and R1 and R2.

[robledjl]

Re: LG LN5700 logo flash then dark screen

Hey thanks once again for the reply. My 4wd was messed up and just like this TV I was doing a lot of trial and error until I bought a new encoder motor and that's what fixed it... I'm not trying to buy a new TV since this one was free lol so the whole time all led's turned on but was still getting the on then off issue, well today after checking the voltage and posting the last message, I flipped the TV over and turned it on and saw that one led was off.... So now that clearly tells me the reason why I'm getting these readings...I thought I've seen somewhere where you can bypass the led with some diodes? Am I correct?

[martino]

Re: LG LN5700 logo flash then dark screen

I would use the stack method,here's a video from our friend reeceyburger:
https://www.youtube.com/watch?v=RxwdC7V5Ue0
Get some popcorn,it's 45 minutes lol

[robledjl]

Re: LG LN5700 logo flash then dark screen

It's the R1. Although I think it would be a challenge since it's the first LED next to were it connects to the other strip.

[martino]

Re: LG LN5700 logo flash then dark screen

That one and the one that they messed with before.Position don't matter,they are all pretty easy to stack.

[odgaf]

Re: LG LN5700 logo flash then dark screen

im a noob too but your problem sounds suspiciously similar to my lg 50inch
i bought mine broken its a 3d smart jobbie, the original issue was it would turn on then soon as i changed channels or volume etc it would switch off, i took it apart overnight disconnected boards etc and it came good for a month, then it started failing to turn on and stay on at night but was sometimes ok during the day,which made me suspicious about its operating temeratures so i went over the powerboard with the soldering iron adding solder to all caps voltage regs diodes and transisters/mosfets and transformers, took 20 minutes and voila shes been running like a dream ever since, i may be mistaken but i believe a cracked joint or 2 was sensitive to ambient room temperatures

[robledjl]

Re: LG LN5700 logo flash then dark screen

Odgaf: thanks for the info, I'm sure I would have tried that since I was running out of patience and suggestions, I didn't want to buy any expensive parts because it was more of a hobby to try to get this fixed with the least money possible. Now that I realize that I do have a bad led, well now I have to see how much I can get one for.

Martino: how much are you asking for the strips?

[budm]

Re: LG LN5700 logo flash then dark screen

Where are you in California?

[robledjl]

Re: LG LN5700 logo flash then dark screen

Riverside County (Murrieta /Temecula)

[martino]

Re: LG LN5700 logo flash then dark screen

I can probably help you with strips,BUT realize they are used and have already unknown amount of hrs on it.
It looks like Budm is up to something asking for your location,I'd wait and see what's up first,with him you are in excellent hands.