Re: LG W2252TQ-PF, high-pitch noise remaining after repair

Hello again,

I just changed the C102 blue cap with an another one, same capacitance but 3 KV.

There is no high-pitch noise while off anymore, this is a progress.

But, there is one similar noise while on, a very feint one. Apparently this sound disappear when the resolution is changing, and return once it has something to display.

It is not a trouble as it is not like the previous sound who was very loud, and even with new caps the rest of the monitor is still old...

Re: LG W2252TQ-PF, high-pitch noise remaining after repair

Hello,

Sorry for the VERY LATE response, computer crashed, bookmarks lost, etc. and life Now I am determined to finish it because if I failed, it goes into the recycle bin in a month at maximum. I need a second monitor asap as the one I had is dead.

So, hum...



I can't be sure at 100%, but I tried to touch the resistances and capacitors near C102 with the screwdriver (with the same ulmost care) but only the HV C102 cap does a reaction : the sound changes a bit, as long...

Re: LG W2252TQ-PF, high-pitch noise remaining after repair

Hello again,

So... I let this thing "sleep" somewhere for a year and I just retried recently. Yes, I am somewhat stubborn

I think I know what is generating this high-pitch noise : the blue cap at location C102 (cf screenshot). It is a 2200 pf 1kV capacitor. It is in the area where the sound come from and each time I touch it with a screwdriver (with caution), the sound change a bit. It is the only one who do that.

As it is a high voltage stuff, I don't have any way...

Re: LG W2252TQ-PF, high-pitch noise remaining after repair

Hello again,

I tried redo some of the soldering, and I even replaced the two 450v 68uF as the sound seemed come from there, but the high-pitch noise is still here.

That means that it is probably the transformer at location T101, the yellow-plastic cube at the middle-right of the first image. It is written AT0471 / LC SA01 L / TF-2820-W52.

Unfortunately, I failed to find a location to buy a new one... Some people said that some glue can fix this problem, but I don't see where I should...

Re: LG W2252TQ-PF, high-pitch noise remaining after repair

Hi,

SteveNielsen, I just tried your idea but I guess that I didn't have a good plastic tube... I think that 1/3 of the board, at the bottom-right of the previous image, has the highest volume with maybe a preference for the coil, but I can't confirm as the tool wasn't great.

Just to be sure, I want to ask two informations from everyone :
- In the first image I attach in this post, I guess that the curiously shaped soldering (not conique) must be replaced ? I can see this shape in multiple...

Re: LG W2252TQ-PF, high-pitch noise remaining after repair

No, I didn't. I only took care of the capacitors.

I will check and redo any suspicious soldering I will find when I have the time Until then, the monitor is unplugged.

Hello everyone,

So... First, I am not an electronic enthusiast, I had few lessons in school several years ago but nothing really technical. No surprise if what I ask in this topic can be easy stuff for you

My previous monitor (LG W2252TQ-PF, an 21" LCD monitor without LEDs @ 1600*1050 / 16/10) died one year and half ago. Before dying and for a good week, he produced an high-pitch noise at specific situations (in sleep mode, even offline but power connected, and between resolution changes) and so I expected it to stop working, and he did. Unable to start it again,...

Re: New Members - please post your introductions here

Hello,

I am Alexandre, from France, 32 years. I am not an electronics enthusiast, just a computer technician who wondered if he could repair an old monitor by himself. I just registered to get more information as the repair is already done but with some remaining symptoms that I don't have any idea of what it can be.

Still, the repair process was interesting and maybe I will do some electronic stuff in the future. I guess that this forum can help me for that with all the already available information...