Monitor dim and burn smell

[thedarkmist]

Hello,
I own a dual monitor set with 2 different samsung monitors. Yesterday I disconnected one while the computer was on (and the other monitor as well) and after about an hour I came back and plugged again the monitor. I discovered that the monitor that was remained on (a Samsung Syncmaster T240) was smelling like plastic burn or something. Now, I can see that the monitor is dimmer that normal. Not black, but it seems the brightness is set to, let say, 60% while it's at 100% indeed.
Can the detouch and reattach of the secondary monitor have cause the damage? Should I investigate for a bad cap or this kind of problem cannot be related to that?
In the next hours I'm going to open the monitor and take some pictures, but... opening it should I have care about not touching the big capacitor on the power card to avoid shocks? Or does it discharges itself when the monitor powers off? Should I use plastic gloves? I have basic skills. I replaced some capacitors on another monitor, and I have solder, multimeter and other basic equipments, but I'm new to practical electonics (I studied it at school, but it was 15 years ago and my job is in the software field).
Kind regards.

[thedarkmist]

Re: Monitor dim and burn smell

Hello. this is the picture of the power board. Capacitors seems all ok, but the problem is in the inverter, in my opinion.
Do you think it worth to change it? Never done a inverter replacement before.

[selldoor]

Re: Monitor dim and burn smell

Ok if it was the inverter transformer it would probably not come on at all.
Do a quick test on it - power off wait 5 mins then measure S1>S2 and S3>S4 on your transformer as in attached

You do not need to remove from the board - find the pins on the back

[thedarkmist]

Re: Monitor dim and burn smell

Ok, but if you see the pucture you can see the plastic is melt and the right side of the inverter is brown colored.

Sorry for the ignorance, but what I have to measure? Impedance?

[selldoor]

Re: Monitor dim and burn smell

Sorry - my error missed a bit out.

Set your meter on Ohms 2000.

[selldoor]

Re: Monitor dim and burn smell

Hello, could you explain me how to replace the power inverter? Is it soldered on the board, or there is some easier connection?
Kind regards.

It is soldered
this is how I removed it.

https://www.badcaps.net/forum/showpo...95&postcount=9

[thedarkmist]

Re: Monitor dim and burn smell

Oh, well, thank you.
Think it's too complicated for my skills...
Thinking about buiyng a brand new power board. :/

[ben7]

Re: Monitor dim and burn smell

Ok, but if you see the pucture you can see the plastic is melt and the right side of the inverter is brown colored.

Sorry for the ignorance, but what I have to measure? Impedance?

Yes, I see the transformer has a melted spot in it. That is evidence of an internal arc. I'd bet that the transformer is the problem! The PCB's commonly turn dark brown, it rarely causes issues.

You might also want to check the blue capacitors in the inverter section for shorts.

Also, you should look at the wires that go to the lamps - just to be sure there was no arcing anywhere else.

-Ben