Please help with a Samsung 2233SW monitor.

[Brian D]

Hello all, I have a Samsung model 2233SW monitor that is a 2009 model year. The monitor started flickering intermittently one afternoon, then upon power-up the next day, it turned on, flashed, and went black. The image is there, visible with a flashlight, but screen is black. If I cycle power to monitor, it will light up for about a second, maybe less, then goes black.

I have read through some posts on this forum regarding similar problems with other monitors (same model) and I am not having much success at repairing my monitor. I have replaced most of the caps on the board hoping for a quick cheap fix. I would have replaced all but the large capacitor on the board, but the kit that I ordered (the kit model number was correct) did not include all of the same capacitor values that my board has. I replaced capacitors and re-soldered some questionable looking solder connections but the monitor has the same symptoms as before.

I temporarily place the board back into the assembly and measured some voltages (12 pin and 5 pin) with power on and power off:

Terminal number: power on / power off

1: 5.13V / 5.15V
2: 18.27V / 17.02V
3: GND
4: GND
5: 5.16V / 5.17V
6: 5.16V / 5.17V
7: 5.15V / 5.16V
8: 2.83V / 0v
9: 3.307V / 3.31V
10: 2.636V / 0V
11: 1.789V / 1.806V
12: 1.789V / 1.806V


1: GND
2: 1.796V / 1.807V
3: 1.795V / 1.807V
4: 2.636V / 0V
5: 3.309V / 3.311V

I also took some measurements on the transformer with the board taken out of the assembly. The terminals are not labeled well, but I had some inconsistent readings. What I think are the secondary pins, measured almost exactly the same (1.162 k ohm and 1.163 k ohm) On what I think is the primary side, I get .2 ohm between the first two, .3 ohm between the next two, and anywhere between 2.50 to 8.55 M ohm between the next two pins. The reading changes and is much different each time I measure it.
Does this describe a bad transformer?
If so, where do I find one?

There are other threads on this forum with photos that look exactly like my board, I will attempt to attach some pics showing mine.

I hope this monitor can be fixed, as I really liked it when it was working........

Any help would be appreciated.

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[retiredcaps]

Re: Please help with a Samsung 2233SW monitor.

The monitor started flickering intermittently one afternoon, then upon power-up the next day, it turned on, flashed, and went black. The image is there, visible with a flashlight, but screen is black. If I cycle power to monitor, it will light up for about a second, maybe less, then goes black.

What you are describing is 2 seconds to black.

I have replaced most of the caps on the board hoping for a quick cheap fix. I would have replaced all but the large capacitor on the board, but the kit that I ordered (the kit model number was correct) did not include all of the same capacitor values that my board has.

The problem with kits is that they don't take into account different board revisions.

Just as an FYI, DYI through Digi-Key is usually 50% less than kit prices.

Does this describe a bad transformer?

Your readings suggest the inverter transformer secondary windings are okay. They are within 3% of each other.

The 0.2 and 0.3 ohms are normal for primary windings and some other pin combinations will result in very ohms reading (normal too). See

http://lcdparts.net/TransformerDetai...ProductID=3944

I will attempt to attach some pics showing mine.

I prefer that people NOT post images inline. About 5 minutes ago, there is another thread where someone posted three 10MB 7676x2083 pictures (30MB of pictures) inline. Within inline, I have NO OPTION, but to view the picture each and everytime I goto that thread. It is like having no skip button on your PVR/VCR to skip past commercials.

Now they are super nice pictures with clear focus and I can understand what the OP was trying to convey, but when my machine slows down to a crawl (and I'm on wifi right now) and my browser starts resizing every 1/2 second, I give up and move onto the next thread which happens to be yours.

So in a nutshell, 2 seconds to black can be

a) bad caps
b) bad inverter transformer
c) bad ccfl wiring (especially the top ccfl return wire)
d) bad ccfls
e) others

All are explained in great detail with posts #19 and #20 at

https://www.badcaps.net/forum/showthread.php?t=10419

Concentrate on c) and d) above.

Note to PlainBill. 30MB of inline pictures and our Coppell discussion.

[PlainBill]

Re: Please help with a Samsung 2233SW monitor.

Note to PlainBill. 30MB of inline pictures and our Coppell discussion.

Yes, I think I'll skip that thread.

PlainBill

[Brian D]

Re: Please help with a Samsung 2233SW monitor.

Now they are super nice pictures with clear focus and I can understand what the OP was trying to convey, but when my machine slows down to a crawl (and I'm on wifi right now) and my browser starts resizing every 1/2 second, I give up and move onto the next thread which happens to be yours.


a) bad caps
b) bad inverter transformer
c) bad ccfl wiring (especially the top ccfl return wire)
d) bad ccfls
e) others

All are explained in great detail with posts #19 and #20 at

https://www.badcaps.net/forum/showthread.php?t=10419

Concentrate on c) and d) above.

I'm sorry about the pictures jamming you up. I will figure out how to attach them properly.

I appreciate the link with more info and will read further. I have some time tonight and will dig in a little deeper.

Regards,

[retiredcaps]

Re: Please help with a Samsung 2233SW monitor.

I'm sorry about the pictures jamming you up. I will figure out how to attach them properly.

It was the other poster. Yours wasn't too bad.

I appreciate the link with more info and will read further.

Take time to read the "case studies" as well. I tried to pick out threads that illustrated the problem a bit more clearly.

[Brian D]

Re: Please help with a Samsung 2233SW monitor.

OK, thanks for the links to the educational material. I read through and performed some tests on the board components....hoping to find a problem without tearing down the screen assembly to look at the ccfl's. I could not find anything wrong-everything seems to test A-ok.

Sooooo, I started the tedious process of tearing down the screen, it is a pretty delicate assembly. I got the ccfl assemblies out and guess what I found? It looks like I have some bad ccfl's.

Any recommendations as to where is the best place to find some replacements? The assemblies have some numbers printed on the backside of the metal shrouds they are:
HWVO (printed in the center)
9408BDF W19X (printed on the wire harness end)



by the way, I think I figured out how to properly attach thumbnails to the post....

[retiredcaps]

Re: Please help with a Samsung 2233SW monitor.

It looks like I have some bad ccfl's.

Only the top one looks bad to me. Alexanna is the king of this type of repair.

Any recommendations as to where is the best place to find some replacements?

Members here have good experience with ccflwarehouse.com.

You can call them and talk to a live person who will help you get the correct replacements. You can buy them "bare" or "pre harnessed". The latter is easier to replace, but more expensive.

If you order the bare ccfl, they have a tutorial at

http://www.ccflwarehouse.com/lasotu.html

As you can imagine, replacing the bare lamp is a very delicate and fragile operation.

by the way, I think I figured out how to properly attach thumbnails to the post....

It makes a huge difference to the regulars who participate in 20 to 30 threads a day. Now that I have chosen to see your picture, I don't need to be forced to see it again (via inline) when this thread gets updated.

[Mikenet]

Re: Please help with a Samsung 2233SW monitor.

Hello Brian D,
I have a 2233sw with the same PCB has your's. I am now about 100% sure it has a bad CCFL.

I checked the inverter impedance secondary and primary and they look ok; (off board)
Replace all the caps with quality caps (except the large one);
Checked the inverter output with CFL lamps (13w) and they all light up and stay on (picture included);

So my next step his to check the CCFL's. How did you proceed to confirm what CCFL was at fault? Tear down the screen and just take a look at them?

Thanks.

[diif]

Re: Please help with a Samsung 2233SW monitor.

Hello Brian D,
I have a 2233sw with the same PCB has your's. I am now about 100% sure it has a bad CCFL.

I checked the inverter impedance secondary and primary and they look ok; (off board)
Replace all the caps with quality caps (except the large one);
Checked the inverter output with CFL lamps (13w) and they all light up and stay on (picture included);

So my next step his to check the CCFL's. How did you proceed to confirm what CCFL was at fault? Tear down the screen and just take a look at them?

Thanks.

Yes, plug in the ccfl plugs one at a time keeping the others plugged into your cfl. It could also be a faulty wire to the ccfl or a failing ccfl.
Then carefully take the screen apart.

[budm]

Re: Please help with a Samsung 2233SW monitor.

You can make two test lamps.
https://www.badcaps.net/forum/showthread.php?t=19987

Bad lamps, wires.
http://s807.photobucket.com/user/bud...?sort=3&page=1

[Mikenet]

Re: Please help with a Samsung 2233SW monitor.

Thanks for the replys,

I connected the CCFLs one by one while keeping the 3 other secondary outputs connected to a CFL. For one of the CCFL's the monitor will go 2 sec to black (2secTB). I guess that's the faulty one (wiring or lamp).

Just curious, for the 2secTB to kick in do you know if the system detects any load imbalance or does it take a absence of load on one of the secondary outputs. Hence I have all 13w CFLs but what if I had a mix of CFL's, 11w 14w etc.

Another question, does it make a difference on what secondary output the CCFL are connected if the secondary outputs have the same specs.

Next step is to get to the CCFLS. Before I do I will clean up the work bench and get the camera. Help's when reassembling.

Thanks.

[Mikenet]

Re: Please help with a Samsung 2233SW monitor.

I got the CCFLs out, they are bundle in pairs (2 X 2). One of them seems bad. It does light up but has this pinkish color.

I switch the CCFLs position on the transformer secondary's with the same result, still the same pink color.

But after cycling the ''on/off'' many times, the bad CCFL lit up ok and has the same white colour than the others CCFLs !

I'm testing it right now, it's been on for 10 minutes with no ''2 sec to black'' but I expect that it will eventually go bad. Reminds me of CFL tubes that sometimes won't ignite and then you get them going but only for a short time.

[budm]

Re: Please help with a Samsung 2233SW monitor.

When it is pink it is bad, after it heats up then the lamp will glow white, you better replace it before it takes out the Inverter transformer.

[Mikenet]

Re: Please help with a Samsung 2233SW monitor.

Thanks Budm,

I need some advice, should I replace all 4 CCFLS or is it a low risk gamble to leave the 3 good ones in place? The monitor is 6 years old.

Attached is a picture of one end of the bad CCFL. There's this ''hot filament'' (that would be the electrode) which look's abnormal...

[Dumah Brazorf]

Re: Please help with a Samsung 2233SW monitor.

Well, at least change the pair.

[budm]

Re: Please help with a Samsung 2233SW monitor.

Thanks Budm,

I need some advice, should I replace all 4 CCFLS or is it a low risk gamble to leave the 3 good ones in place? The monitor is 6 years old.

Attached is a picture of one end of the bad CCFL. There's this ''hot filament'' (that would be the electrode) which look's abnormal...

When the lamp is bad, it will glow like that (and sometime when it is really bad the glass will crack or deformed, and solder at the end of the tube will be crystallized and wire and the silicone boot will be over heated), there is no filament in the CCFL.

[Mikenet]

Re: Please help with a Samsung 2233SW monitor.

I shopped around for CCFLs. It seem's that they are either quite costly or not costly if you buy from a China supplier.

Anybody has some experience or advice based on facts.

I don't mind paying more if it's worth doing so.