Help with monitor that works and doesn't work...

[walterg74]

So I have this older LED Monitor, a Samsung XL2370.

Since I was not using it, I actually put it up for sale. Tested it first, seemed to work fine, and someone bought it.

The guy called me the same day because it shut itself off, maybe like seconds after an image first appeared. If you turn it off and back on, the image appears and the dissapears gain.
Note the the monitor does not power off, it is still on but the image is gone.

So he returned it, gave him his money back and now I am testing it. I'm finding some weird things...

I saw the same behavior, after a while the image did come up so I thought it was one of those issues that it had to "warm up" or something.

But then when the image dissapeared, I noticed that it was still there but very very faint. But what's even weirder, if I changed the image mode to the preset "dynamic contrast" the image came back!

It only works with this mode. If I switch to a different one it dissapears again! I tested it like this yesterday, leaving a movie in a loop constantly and it was running for about 8 hours straight, image always on.

I shit it down and this morning I went to try again and the same, no image, but after a while it did appear again, and works just fime in dynamic contrast mode only.

So.. Wth?

Anyone have a clue..?

 

[Capitan Harlock]

Does this thing with every input?
If the monitor was not in use for a log time could be that some dust is inside the monitor ?

 

[BiggieShady]

I bet it has touch buttons.
One of the touch buttons, probably for contrast, went bad and it's in always on state and it's constantly driving contrast to zero, that's why faint image and why dynamic contrast works.

 

[Bill_Bright]

It sounds like an inverter problem - but being LED and not CCFL, it does not have an inverter. So I'm with Q, I mean BiggieShady and if me, I would get some electrical contact cleaner, open the case and clean the button contacts - then hope for the best.

I shit it down

I bet that hurt!

 

[jaggerwild]

The CAPS are old the image disappears(turns off after powering on)is the tip off, in a short verse the unit is dying. It needs a CAP kit installed, more then likely they are in the built in power supply or the main board. Inverters do go bad, but usually if this happens he has more then one in the unit, so he would get a partial image. They can be tested by opening the monitor which is a whole other can of worms.
Here's alink to a site if you wanna get it fixed, by you or someone else. http://www.badcaps.net/forum/index.php

Hit me up with a PM if you wanna chat on the phone and your serious about getting it done. I do this stuff a lot, would even consider doing it for free(unless your greedy)then you get charged...

 

[AsRock]

It sounds like an inverter problem - but being LED and not CCFL, it does not have an inverter. So I'm with Q, I mean BiggieShady and if me, I would get some electrical contact cleaner, open the case and clean the button contacts - then hope for the best.

I bet that hurt!

Could be all so the crappy caps that Samsung put in their stuff too. It's very common and lost count how many i have fixed including my own 204B due to the issue.

You can normally get the kits of Amazon, although not sure if ones available for your monitor.

 

[Frick]

I dunno about caps... Would the dynamic contrast thing work fine if it were the caps?

 

[McSteel]

Damn.

I had just typed out a huge post about recapping the power board, then I checked and found that the XL2370 uses an external power brick!
If I'm not mistaken, that power adapter is a 12V, 3A (36W) one. Could be a 12V, 4A (45W) one instead... OP, can you confirm?

If so, you could:

a) find a compatible power adapter and try using the monitor with that one instead.
b) in case you're feeling adventurous, you could use your PC PSU to power the monitor - use the power adapter's cable to connect your monitor to a Molex or other 12V-carrying plug on your PC PSU.

Of course the monitor does have voltage regulators inside that bring the input 12V down to 3.3V and 5V for the logic board and the LED driver circuitry's needs, so those could've gone bad in theory. In practice, those regulators are usually fully solid-state (SMD Tantalum and polymer caps) so it rarely ever happens. I'd check the power brick first.

Oh and as for why it works with dynamic contrast, it's simple - the power draw is a bit lower in that case and only sporadically spikes. Also the power draw pattern is different, probably enough so as to relieve the stress on the most likely failed filter caps in the power brick.

 

[Bill_Bright]

I've not seen where Samsungs are any worse than any other brand - especially if you compare Samsung entry level monitors with any other entry level monitors.

I've got a 204B, btw. Bought it new in 2006. 10 years old and still going strong. And the two Samsung 2220wm monitors I bought in 2008 and now have on this system refuse to die so I can replace them with two 24" Samsungs I have my eye on.

I never buy entry level monitors, but I don't buy the top-tier lines either. All I can say is I've had better luck with Samsung than I have had with LG, Dell or ViewSonic. And by luck, I mean in terms of failure or dead pixels. In fact, I never had a Samsung with a dead/stuck pixel. Maybe just luck but I cannot say the same for LG, Dell or ViewSonic. That said, if I had to choose something other than Samsung, Dells have been good too.

 

[qubit]

Yup, it's a faulty monitor all right and unlikely to be worth the time, effort and money to fix it.

 

[jaggerwild]

Samsung uses cheap caps, open yer TV n see! All you people give is opinions, I'm talking about fixing it. Have at it I'll un-flow, hope all YER OPINIONS fix it good! Caps wear out over time, why you think PSU go bad? Lose there charge, I'm an engineer what do I know................OH external PSU for the display still contains CAPS, like playing BF 4 team in here everyone working against each other. I want that I'll go back to hanging out at EVGA forums.

 

[Bill_Bright]

Samsung uses cheap caps, open yer TV n see!

Oh, you mean my 10 year old 46" Samsung that still looks and works great and has never needed any sort of repair?

I say open your competing model by Vizio, Acer, AOC, Dansai, LG, Insignia, JVC, Sansui, Sanyo, [fill in the blank], or even Sony and you will see the same quality caps. But like the other brands, not all models are the same. Higher end models don't just have more features - they also use better quality components - where needed.

Oh, and sorry, but being an engineer just means you know theory. Big difference from understanding the "applied" sciences. For example, "cheap" does not imply poor quality components that will fail prematurely. When it comes to manufactured products, electronic devices, in general, are pretty darn reliable - even cheap ones. Of more importance is circuit design, soldering/assembly techniques, and proper selection of components. If the "cheap" cap is properly sized and adequately cooled, there is no reason to suspect it will fail prematurely.

Caps wear out over time, why you think PSU go bad?

Ummm, all electronics wear out over time.

 

[jaggerwild]

You a 10 year old 46 inch lolz! NUFF said!!!

Oh I don't have a paper says I am, I only worked on thousands of slot machine's for a major distributor...................I guess if I had more posts I'd know what I was talking about like you.
http://hwbot.org/user/PhIlLy ChEeSe StEaK/#Hardware_Library

 

[R-T-B]

Oh, you mean my 10 year old 46" Samsung that still looks and works great and has never needed any sort of repair?

I say open your competing model by Vizio, Acer, AOC, Dansai, LG, Insignia, JVC, Sansui, Sanyo, [fill in the blank], or even Sony and you will see the same quality caps. But like the other brands, not all models are the same. Higher end models don't just have more features - they also use better quality components - where needed.

Oh, and sorry, but being an engineer just means you know theory. Big difference from understanding the "applied" sciences. For example, "cheap" does not imply poor quality components that will fail prematurely. When it comes to manufactured products, electronic devices, in general, are pretty darn reliable - even cheap ones. Of more importance is circuit design, soldering/assembly techniques, and proper selection of components. If the "cheap" cap is properly sized and adequately cooled, there is no reason to suspect it will fail prematurely.

Ummm, all electronics wear out over time.

Bill, I respect you and all, but badcaps.net has thoroughly documented Samsung as being a purveyor of bad caps, particularly CapXon brands. Particularly putting low quality caps in a internal power supply near the back light area where they get wicked hot. You know what heat does to electronics? I think you do.

It's not exclusive to Samsung no, but it is one of the biggest players to do it. Mind you, even bad cap brands can last 10 years, they just don't tend to do so on a large scale...

 

[rtwjunkie]

I just have to say, of all the TV brands I've checked the picture out on, the Samsung had the picture wuality I liked the most. I'll keep using them, even if they supposedly have bad caps.

I'm not going to replace with what I perceive to be a worse picture quality just for better caps.

Anyway, this is about monitors.

 

[Bill_Bright]

It's not exclusive to Samsung no, but it is one of the biggest players to do it.

I think the important thing to note here is that Samsung is one of the biggest players in the first place.

There are more Ford pickup trucks in for repair than any other brand. But it is not because they use inferior parts. It is because the Ford pickup has been the number one selling vehicle in the US for the last 30 years. With more of them on the road, there will be more breaking down. Same with Samsung.

I am not saying Samsung is the most reliable product out there. In fact, some reliability studies put them at or near the bottom. But then at the same time, some customer satisfaction surveys put them at or near the top. ConsumerReports, based on over 90,000 TVs bought by over 64,000 subscriber, ranks Samsungs, in terms of reliability on par with Sharp, Philips, LG, Seiki, JVC, Sanyo, Insignia, and Haier with 4% of the sets requiring repair. Hitachi, Panasonic, Emerson and Sansui topped the list with 2% (Sony had 3%).

But the fact of the matter is, electronics in general are pretty darn reliable compared to 30 - 40 years ago. Even the worst, Westinghouse and Sceptre came in with 6 and 7% respectively.

We (those of us in electronics and computers) are constantly harping on quality PSUs from reputable makers. But the fact of the matter is, there are still millions of very old computers with no-name, generic, barely adequately powered PSUs out there still chugging along just fine.

You know what heat does to electronics? I think you do.

You can trust by the last line in my sig that I do indeed know what heat does to electronics.