LG 23EA53 black screen after one second, it works after 5 minutes, high pitched sound

[rattlesnake]

Hello people,

When I turn the monitor on I can see the image for a second, then the screen becomes all black.
If I let it sit there and wait about 5 minutes, then I turn it off and back on again, it works normally.
But there's a hissing sound all the time, very high pitched sound.

I've been using this monitor for about 5 years.

Due to all these signs I think this is a bad capacitor.

I attach pictures of the PCB with the capacitors so you can judge and advice me what to do. Does any capacitor look bulged? Only (and slightly) the 100v 33uF one.

Any help will be appreciated!

All the capacitors I've been able to identify:

1:
2DQJ
33
100

2:
3A
VZH
68
35V

3,4:
3A
100
16J

[frica]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

I am in agree with you that the capacitor of 100v is slighly bulged. But remember that often capacitors could be bad with no visible evidence (bad capacitance or ESR).

[R_J]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

The 33µf 100v, is the main filter for the led string voltage. It is likely bad, those little caps don't have much inside to make much of a bulge

[rattlesnake]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

I replaced the 100v capacitor with a new one (it took a while to arrive).
It didn't make a difference. Actually, I ended up removing all caps to check them and all were in spec.
Put them back on, nothing changed except now I don't get the screen working for a single second.
There's this hissing noise, pretty intense.
I removed all caps and turned it on, the noise is still there.
I recorded it and amplified it, it's here:
https://vocaroo.com/i/s0J6krASxfBM
It has some kind of pulse/rhythm to it.
I really wonder where could it come from, what could cause it. What could be broken?

Could one of these components be the culprit? If not, what?

I attach high res pictures of the components.
I managed to identify some of them:

8839BMP-C
25008M
https://cdn.badcaps-static.com/pdfs/...06d1e02bd3.pdf
https://cdn.badcaps-static.com/pdfs/...43855437b3.pdf
VOLTAGE REGULATOR (PROBABLY)

208022-TI-31A-P06564
NO IDEA

D478-BA262Z
MOSFET


W25X40CLSNIG - Flash ROM


TROQ - 14.3H007
CRISTAL

4R7
Signal transformer
https://www.digikey.dk/product-detai...4R7-ND/2777571

330
DKzC1
Probably signal transformer too.

PJ3049
BR210
Rectifier diode

Resistance

Some unidentified fuse?

I know very little about electronics, so please excuse my ignorance and any blatant error.
Further information about how to diagnose the problem would be very welcome.
Thank you for your help to get this monitor working again!

[Ezequiel_]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

Hi, Rattlesnake!
Yesterday I have the same fail.
Change de external switching! In my case the output voltage drop down to 16 V when it is connected.
I use now a old notebook switching that it have outvoltage 18.5 V, and work very well.
I hope this help you.
Best regards!

[rattlesnake]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

Hi, Rattlesnake!
Yesterday I have the same fail.
Change de external switching! In my case the output voltage drop down to 16 V when it is connected.
I use now a old notebook switching that it have outvoltage 18.5 V, and work very well.
I hope this help you.
Best regards!

Thank you Ezequiel! I changed the two same value capacitors that had a high ESR value, then, replaced the PSU and... it works fine!
I had to be careful with the flex cable because if it's not taped to the back of the LED panel tightly it shows artifacts in a strange green hue... gladly it got fixed upon using some scotch tape.

Thanks everybody!

[morfeas123]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

HELLO everyone...need to know 208022-TI-31A-P06564
NO IDEA what this is.if someone has the repair manual please contact,thank u!

[lotas]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

hello everyone...need to know 208022-ti-31a-p06564
no idea what this is.if someone has the repair manual please contact,thank u!

ic102 - SN1208022 (sop-8).

[morfeas123]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

oh thank you soooooo much.

[morfeas123]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

but unfortenanly i cant find the same.what are the specifications to find something that could do the same.sorry but im novice.just learning now.thanks again

[morfeas123]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

and in the service manual there is now replacemant parts list so i know what kind of ic this is to get something simular.

[morfeas123]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

so please if someone knows please help!

[lotas]

Re: LG 23EA53 black screen after one second, it works after 5 minutes, high pitched s

On the forums they write what can be replaced with:
TPS54339E and on APW7302B.