LG Flatron W2353V - Two hours to black

[CuriousOne]

First of all, I wanna say hello to this great forum and its inhabitants. Found some interesting readings here through google, before decided to register myself.

Now to the point. Bought this monitor new in 2009. Served flawlessly for 3 years, until started to get sleepy. First it happened once in a couple of weeks, then days, now it's hours and minutes.

How it looks
Screen suddenly goes black. Power LED still shows active state, but all of the touch sensitive controls are unresponsive. After reconnecting power cable monitor might turn on, but for a while. Working time decreases with each reconnection, until it becomes minute or two. After resting for a couple of days it's again hours (looks like some capacitor related behavior to me).

What I tried
First thought about some software problem (drivers, DVI frequency bug, corrupted EDID, etc). No result.
So here comes hardware. Didn't managed to see anything with flashlight. After opening I saw one bulged cap on power board and blindly changed most of them (six middle-sized). Still the same.
Checked voltages, using service manual and circuit diagram. Luckily, I can check board in both normal and "sleepy" state, so there is a small table.

			| Normal	| "Sleepy"	|
+22V/GND		| +22V		| +27V		|
+5V/GND			| +5V		| +5V		|
T301 (first winding)	| AC 588V	| 0V		| (Using a legacy multimeter. According to manual has to be AC 700Vrms)
EN/GND			| 3.3V		| [COLOR="Red"][B]0V[/B][/COLOR]		|

Last number is highlighted, because until this I was almost sure the problem is with inverter. But now, seeing that control pin supplied by logic board is zeroed got me mixed up.

Any help, suggestions or even personal successful experiences will be much appreciated )

Specifications and photos
Monitor
Model: LG Flatron W2353V-PF

Power board
Model: AIP-0192
Revision: F
Inverter IC (U301): MP61093ES
Inverter transformer: EEL-22W
U101: LAF0001 VJ46

Logic board
Model: EAX58159501(8)
Safety Mark: W53/54V
IC101: TSUM088GDI-LF-1 AFV05259990

[jetadm123]

Re: LG Flatron W2353V - Two hours to black

Could be bad caps or bad solder joint. Try heating various sections of both the power supply and logic board with a hair dryer to see if can accelerate the shutdown process. Hopefully, it will help you narrow down the area of the board that's causing the problem.

[CuriousOne]

Re: LG Flatron W2353V - Two hours to black

Changed another cap on power board. Also redid soldering on some suspicious joints, but nothing obviously criminal. Tried hair dryer thing, but didn't saw any direct effect. Nevertheless, I don't have any experience with this, so here is what I did.

Turned on monitor and started heating power board for couple of minutes - no effect, switched to logic board and after some time monitor turned black (could be coincidence, because of time). Next try - same result, just shorter time period. Tried another technique: preheat board before turning monitor on. No effect - every time it starts normal and works for some time.
It's +28(C) outside. Heated from both sides. Every time heated until at least 60+(C) (almost hurts when touching).

I hope this gives you any glue.

[jetadm123]

Re: LG Flatron W2353V - Two hours to black

Hopefully, the replacement caps you're using are low-esr types like Panasonic FR/FM/FC series.

Also, have you tried replacing any of the caps on the logic board?

On your voltage chart, you have a voltage listing for "sleepy state" Do you mean the sleepy state is the same as when the screen goes "black"?

[CuriousOne]

Re: LG Flatron W2353V - Two hours to black

Hopefully, the replacement caps you're using are low-esr types like Panasonic FR/FM/FC series.

I wish they were, but they are some unknown to me brand from local store. The old ones were Su'scon SK/SG series, are they considered low ESR?

Also, have you tried replacing any of the caps on the logic board?

Not yet, but now I'll buy them as soon as possible. Also, there is one small SMD type cap on logic board, should I change it too?

As for the voltage chart - yes. "Sleepy" means that I waited until monitor goes to its faulty state and then checked voltages on board.

[jetadm123]

Re: LG Flatron W2353V - Two hours to black

Looks like the power supply is working correctly. Your EN/GND reading must remain at 3.3V in order for the monitor to stay on. At this point, I'm inclined to believe that the logic board is at fault and replacing the caps would be a good starting point. You can probably leave the SMD alone, unless it's shorted or broken.

[Titoftit]

Re: LG Flatron W2353V - Two hours to black

Hi CuriousOne,

I have same monitor with a similar problem.

I want to know where are you find the circuit diagram, please ?

Thanks

[CuriousOne]

Re: LG Flatron W2353V - Two hours to black

I want to know where are you find the circuit diagram, please ?

I don't remember where I found these, but here they are in attachments. Just be advised, that some components on these diagrams differ from those on my board (perhaps different revision). Also, I would be glad if you'll post your progress.

As for my progress, I changed most caps on logic board without success. Thanks to jetadm123, it's obvious to me now, that power board has nothing to do with that fault. Nevertheless I'm stuck.

And for some good news: in the meantime I succeeded in repairing another monitor (MAG 900P, had bulged cap and burned MOSFET).

[budm]

Re: LG Flatron W2353V - Two hours to black

Monitor that EN (backlights on) to see if it goes away when the backlights go out. 0V = OFF.
Do you also hear any arcing sound from the LCD panel?

[enghijjawi]

Re: LG Flatron W2353V - Two hours to black

plz anyone help me
I'm looking for LG Flatron W2346T service manual.

[idanudel]

Re: LG Flatron W2353V - Two hours to black

hi CuriousOne did you solve the problem? i was face the same problem, but now my screen is dead now.. its not turning on at all..

[marlosdamasceno]

Re: LG Flatron W2353V - Two hours to black

Hi CuriousOne!
Did you solved the problem?
I have the same problem that you (100% equal), but I can't find the solution by my self, now I just study electronics and I don't have enough knowledge to fix =/
Well, I wait for your reply.
Thank's

[eriksimoes]

Re: LG Flatron W2353V - Two hours to black

Hi, sorry to re-start this topic.

I´d like to know if someone was able to sove this issue, I have the same problem on my w2353v.

Thanks,
Erik

[spidey]

Re: LG Flatron W2353V - Two hours to black

i think thats a ccfl problem, or maybe inverter. try another known good LCD Panel. Also check BG ON/OFF signal. if there is 3v but still no screen then check starter circuit.

[Equilibrium]

Re: LG Flatron W2353V - Two hours to black

The faulty on my LG W2353V was the Inverter. I replace it, and it power on with something on screen.
I notice that the Inverter become very hot after a few minutes, but not dying after couples days of usage.

The date printed on the Inverter board AIP-0192 is 2008/12/24.

Thank you

[opala4cc]

Re: LG Flatron W2353V - Two hours to black

Equilibrium:
I didn't understand if your monitor had the same behavior than the CuriousOne. You just told you replaced the inverter and solved the problem.
I have the same inverter board than you and the CuriousOne, so the same problem with a LG Flatron w2353V.

[turcobom]

Re: LG Flatron W2353V - Two hours to black

I have had the same problem. After the replacement of all capacitors of the power supply, the monitor came to work properly again.

[turcobom]

Re: LG Flatron W2353V - Two hours to black

Unhappily the problem was not fixed with the replacement of the power supply capacitors. After some hours of use the monitor failed again.
Then I realized that the 1.8V (IC303 pin 4) of the Control Board drops to approximately 1.1V when the fail appears. Then I disconnected the IC303 pin 4 from the board and I supplied the 1.8V with an external power supply and the monitor started to work again. My next step will be to replace the IC303 of the Control Board.

[R_J]

Re: LG Flatron W2353V - Two hours to black

Your problem could be with ic301, the 1.8v regulator or more likley C307,C308, C324 or C325

[televizora]

Re: LG Flatron W2353V - Two hours to black

Yep, replace the 1.8V Voltage regulator and caps nearby. If the power to the MC is not stable, anomalies start to show up.