Samsung monitor blow out

[dosyl]

Hi everyone,

I have an LCD computer monitor that suddenly stopped working. I was using it and the sound of an explosion was heard; then nothing, no more image and the LED on POWER neither. It's been about 6 months since this happened. I decide to repair it.

Samsung model: 2493HM

I thought it was the LCD tubes that were broken, but today the POWER (standby) LED flashed.
I believe it's a capacitor, but nothing visual; I thought that with the sound it made, I would see parts shattered, but no.

My idea is to start testing the capacitors on the power side, because by disconnecting the wires connecting the screen, the LED (POWER) still flashes.
I plugged in my laptop to test, and my laptop sees the screen, but nothing appears naturally.

-----------------------
Here is a photo of the fault, why it failed.
Resistance.


Another question:
The resistor which is burnt is .22 ohms, I have some (I know they are Chinese
their measured value is between .4 and .6 ohms wound resistors; is it so serious?

Otherwise I have ordinary resistors of .33 ohms and to measure give .5 ohms.

What is your opinion?

 

[danadak]

The large brown bulk capacitor seems to have a slight bulge at top,
indicating it may have failed, quite often as a short. So they take out
other components often when they do.

The resistor is a .33 ohms resistor if it is still good.

Regards, Dana.

 

[dosyl]

The large brown bulk capacitor seems to have a slight bulge at top,
indicating it may have failed, quite often as a short. So they take out
other components often when they do.

The resistor is a .33 ohms resistor if it is still good.

Regards, Dana.

The resistor .22 ohms have a missing and burned piece. The big capacitor is very flat on top.
My little question is can I replace a .22 ohm with a .22 ohm that is not the good value when measuring. They have all .4 ohm or so

 

[Martaine2005]

You can’t measure a capacitors ESR (equivalent series resistance) with a multimeter.

 

[dosyl]

You can’t measure a capacitors ESR (equivalent series resistance) with a multimeter.

I have a tester for esr, but I'm talking of the resistor on the picture.

 

[danadak]

I am strictly guessing here but I would posit that R is used as a shunt in a feedback
loop to control the LED power or current for the LCD backlight. You could
always use a gauge of wire and cut it to length to get .22 ohms.

Definitely measure the C ESR to make sure its OK. Look online for
its spec. The ESR meter also should be able to give you the R
value. Check its specs.



Regards, Dana.

 

[dosyl]

Bonjour à tous,

Je vous envoie des lectures concernant mon moniteur, car je n'ose pas le brancher avant d'avoir trouver la raison que 2 transistors ont sautés ainsi que la résistance de .22 ohm. Je ne sais pas si du coté négatif ce doit être les mêmes lectures. Sinon je brancherai et "kabooom"

Voici ce que j'ai identifié sur les photos:

Valeurs des lettres en ohms

Entre A et B 143 ohms

Entre C et D 23 ohms

E Résistance de .22 ohms qu'il y avait car elle est sautée

F Résistance de 473 (47 k) que je pensais en court-circuit, mais elle est correct.

https://ibb.co/My4rj3kk

https://ibb.co/v40PVBbh

Je ne sais pas si la valeur de 143 ohms et de 23 ohms c'est correct; une différence de 120 ohms par rapport au positif et négatif.

Merci de me lire et m'aider

 

[bertus]

Hello,

This is an english only site.
Translation by google:
Hello everyone,

I'm sending you some readings for my monitor because I don't dare plug it in until I figure out why two transistors and the 0.22 ohm resistor have blown. I don't know if the readings should be the same on the negative side. Otherwise, I'll plug it in and "kaboom"!

Here's what I identified in the photos:

Letter values in ohms

Between A and B: 143 ohms

Between C and D: 23 ohms

E: 0.22 ohm resistor that was there because it's blown

F: 473 (47 kΩ) resistor that I thought was shorted, but it's correct.

IMG-0813 hosted at ImgBB

Image IMG-0813 hosted in ImgBB

ibb.co

IMG-0815-Modifi-1 hosted at ImgBB

Image IMG-0815-Modifi-1 hosted in ImgBB

ibb.co

I don't know if the values of 143 ohms and 23 ohms are correct; A difference of 120 ohms between positive and negative.

Thank you for reading and helping me.

Please use english in replies.

Bertus