Samsung S27C750 - Did I decode these caps properly?

[Donkeyramp 1]

Greetings all,

I've been trying really hard to figure this one out on my own and I'm finally throwing in the towel. But not before I at least take a stab at it first. So I have a board from a Samsung S27C750 monitor and when I turn it on, I just get a black screen. It slowly started losing its life to the point where you turn it on and nothing happens. For a while, the screen would turn off then back on and do weird stuff like that. Everything I read pointed to bad caps. They don't look bad, I don't see any signs of leaking or bulging or anything, but I figured I would try and replace the caps anyway. Only I didn't realize identifying them would be the massive headache it's turned into. So anyways on with the show I'll post some screens of the caps. The first one I guessed would be a 100 uf 25v? Almost seems a bit too obvious to be right though. And the second one I went with 10 uf and 100v. I'm almost sure the voltage is right on that one but not sure about the capacitance. Any help would be appreciated. Thanks!

[SMDFlea]

Re: Samsung S27C750 - Did I decode these caps properly?

A similar thread to this one - https://www.badcaps.net/forum/showthread.php?t=57285

Check the voltage first on the power adapter.Please provide good clear straight pictures of the whole top and bottom side of YOUR board.

[Donkeyramp 1]

Re: Samsung S27C750 - Did I decode these caps properly?

I'm literally running out the door at the moment so I'll have to check the power adapter when I get back but here is the shots of the board. Thank you!

[R_J]

Re: Samsung S27C750 - Did I decode these caps properly?

The cap in the first picture is 100µf/25v, the second is 10µf 100v (2A=100v) This cap is likely for the led boost voltage, and if bad would shut down the backlight.
It could be that you have a fault with the power adaptor and not on the main board.

[momaka]

Re: Samsung S27C750 - Did I decode these caps properly?

It could be that you have a fault with the power adaptor and not on the main board.

Possible.

This is where the good old hair dryer trick can come in handy.

Take a hair dryer and heat the board to a point where it feels warm to touch, but nothing is burning you hot. The try powering on the monitor to see if it will come on. (And let us know what you observer.)

Basically, as electrolytic capacitors start to fail from age and/or use/heat, their ESR/impedance will start to go up. Warming the capacitors, however, causes their ESR to decrease. So a lot of times, if the capacitor hasn't completely failed yet, the heat from the hair dryer will decrease its ESR... and sometime that can be enough to get the device functional again.

So if your monitor does happen to work after the hair dryer trick, consider replacing those small caps (or at least soldering new ones in parallel with these, if you can't get them removed.) However, if the monitor doesn't appear to work, then we need to see if there isn't something else that is causing the issues you have with your monitor.