I think Backlight burnt out?

[Outlier_81]

I have 2 LG 27'' displays that I bought 3 years ago. (Literally - I just posted a review about them saying how I haven't had a problem, after realizing I had them for 3 years. jeeze)

Today one of them made a sizzle/frying/popping noise, looked like a brownish burnmark went across the screen, and then it shut off.

I tried turning it back on a few times since then, it'll come on for like 2-3 seconds and then shut off. The burn mark is still there.

How do I know if it's a Back light that just burnt out, or if it's a completely different problem?

I'd like to fix this if possible... if not I'd have to buy 2 more screens, because I'm very picky about the displays being the same.

 

[06yfz450ridr]

if its just the backlight you will still be able to see your screen if you use a flashlight to look at it. if you dont see anything its probably both the backlight and screen are bad. most of the time its just the inverter that goes for the backlight but you will need to buy both pieces. its an easy fix tho if you are comfortable taking things apart

 

[Kari]

sounds more like a capacitor failed quite spectacularly and popped open... you'd need to open the casing and have a look inside to really see what part failed, based on the noise there will undoubtedly be some visual/physical damage so identifying the failed part should be quite possible. If it really is just some common capacitor replacing it should be relatively easy if you've ever done any soldering before.

Dont suppose they are still under warranty anymore...

 

[getochkn]

What type of TV? What is the model number. If it's LED, there is no backlight. If it's LCD and it was the backlight, you would be able to turn it on and see very faint picture when looking at it, or looking at it with a flashlight.

Probably a bad cap as said above, it's a notorious problem with TV's, especially ones from a few years ago. They have gotten their cap issues better over the past couple years, but a 3 year old TV seems prime for a cap failure as said above.

 

[Outlier_81]

Model Number: W2753V

It's a monitor, not a TV. It's LCD.

I'm going through a disassembly guide right, I'll try to give some more info when I get it open.

 

[Outlier_81]

Okay I've got it open and I got the power board out.

From what it looks like, all the capacitors are fine (they are the bigger black ones right?. There is some noticeable browning around this piece (I'm not big into electronics, so I have no idea what it is) so here's a picture: http://i.imgur.com/Gr87rxU.jpg

The video I'm watching doesn't explain what it looks like "if it failed". I'm assuming the browning around this isn't good or normal though.

 

[Outlier_81]

Update: After watching his next video, it looks like his board has that same browning. So I'm assuming mine is fine.

Not sure how to tell if these capaciters failed though...

 

[getochkn]

Well if you have two of the same TV's, and one works, swap power board from the working one, see if it fires up in the non-working one.

 

[Outlier_81]

It was pretty difficult opening this one... the bezel snaps in and I snapped a few of them off while trying to open this one. I'd prefer not to open my fully functioning one if possible. Although that would be ideal.

after google, it seems like bad capacitors look like they are rounded/bulged. I've got 3 of them here that look like that.

 

[Kari]

after google, it seems like bad capacitors look like they are rounded/bulged. I've got 3 of them here that look like that.

yeah, but I'm not entirely sure the noise you heard came from those if they are only bulged, I would have expected the top to be torn open at the grooves... It's definitely worth replacing them either way.

 

[getochkn]

after google, it seems like bad capacitors look like they are rounded/bulged. I've got 3 of them here that look like that.

yeah, but I'm not entirely sure the noise you heard came from those if they are only bulged, I would have expected the top to be torn open at the grooves... It's definitely worth replacing them either way.

Ya, a buldged cap should only not turn on the next the time you go to turn it on, make it turn on/off real quick, standby light flash, etc. Not short out mis-usage and crackle and smoke. Could be another part too. I'd still work on getting the working apart very carefully and swap the PSU. Best thing to determine if that's it or without trying to replace caps or anything.

 

[Outlier_81]

Okay another update... I finally got some capacitors ordered in... Changed them out. I only changed the ones that looked bulged.

Now when I turn it on there's 2 pixel lines that run down the middle of it. One is green, one is pink. It only stays powered on for a fraction of a second and shuts back off.

It looks like there's a darkspot that runs all the way across the screen (like it did in the original post).

Anyone know what the pixel lines are from.

Also how do I troubleshoot this further?