Samsung 2223NW - lines and broken image [pic included]

[DeerDance]

• would not start at all
• replaced six 470uF caps, three of which were bulging
• afterwards it starts but image has colorful lines and is generally broken

Any ideas on what to focus next?

[R_J]

Re: Samsung 2223NW - lines and broken image [pic included]

You replaced 6 caps, I see 9 caps, I also see 5 caps on the main board, start by replacing the caps C138, C103 and the one between these two next to the regulator ic's on the main baord

[DeerDance]

Re: Samsung 2223NW - lines and broken image [pic included]

Thank you.
I replaced three remaining caps on the powersupply board, two were 680uF and I did not have those, so I used 1000uF instead to just check and see what it does. Then moving to the other board...
The monitor started with very bronken changing colorful lines.
Wanted to take photo for the forum to update, but afterwards when I power it up, it started absolutely normal - fixed.

I guess the caps got charged and act more normal than the first cold start, will got buy 680uF tomorrow and put those there. Will see if it will be "fixed" tomorrow too.

I also learned that pressing power button for few seconds before disassembly does not always discharge the caps and got healthy kicked few times.
Measured voltage on the big one at around 350V. Discharged using resistor.

I fixed few monitors before - replacing buldged caps, replacing a nano fuse, replacing a transformer. Never got kicked before so I kinda just assumed that the pressing of the power button without power did its job. Dumb me.

Thanks for reply!

[Davi.p]

Re: Samsung 2223NW - lines and broken image [pic included]

I guess the caps got charged and act more normal than the first cold start

This has not any sense, i guess there is a contact problem on the lvds connectors.

[DeerDance]

Re: Samsung 2223NW - lines and broken image [pic included]

Ok, its back with vengance, I got 680uF and put them in but still random lines
any tips what to check next after caps change on the power board if this is how it looks?



I am going for change of the caps on that other board now

[R_J]

Re: Samsung 2223NW - lines and broken image [pic included]

Caps on the main/logic board can cause this, it is usually the low voltage regulator ic's that can oscillate at high frequency when there bypass caps go bad as in almost open.
There look like there are 3 caps near the two regulator ic's. These small caps usually look ok because they don't bulge or leak but they DO dry up.

[DeerDance]

Re: Samsung 2223NW - lines and broken image [pic included]

Ok, update after 1 hour of dicking with those little shits with bend legs.

All caps on the logic board are replaced

3x 22uF
2x 100uF

old ones had really high resistance, one was 22 ohm another 12 ohm
I assume this is high considering new ones are like 0.X or 0.0X ohms

Now, after I switched it on the first time it was still fucked.
After switching it up second time normal image appeared,
it is the very same behavior like with the first cap change on the power board.

Will see, tomorow I try to run it most of the day

[DeerDance]

Re: Samsung 2223NW - lines and broken image [pic included]

OK, not much testing done as the moment I turned in on I noticed that theres some color/pixel issues.
Like if pixels were 20 times larger with 8bit colors resulting in banding...

Yesterday I did not notice, as I was just looking for the moving square telling me no signal.

This is the bad one


This is how it suppose to look on a good one


Play with the control board and you pay the price.