On May 3, 4:01*am, "N_Cook" wrote:
Jeff Liebermann wrote in message

...



On Sun, 2 May 2010 17:53:14 -0700 (PDT), saber850
wrote:

On May 2, 5:10 pm, Jeff Liebermann wrote:

This might be of interest:
http://pavel.kirkovsky.com/2009/03/samsung-syncmaster-204b-repair/
http://www.djhome.net/tips/samsungsyncmaster204T.htm
I've seen both problems on the bench with similar Samsung models.

This is great info; thanks. *The website links you found refer to the
problem as "flickering". *Is that the condition my monitor has, given
the video I posted?

No, it's not the same. *What's probably happening is that as your
power supply warms up, the cazapitors are starting to also get hot. My
guess(tm) is that the power supply output voltages drop, causing the
odd changes to white and black. *The symptoms of having the wrong
power supply voltage vary radically with the type of circuit and which
capacitors are a problem. *I've seen flickering, fades, time delayed
sudden failure, smoke, fire, and most commonly, just plain no picture.
Given a specific single component failure, it's possible to predict
the symptoms. *Given multiple partial failures, it's at best a guess.

Open up the monitor (it's a royal pain), replace all the big caps
whether they look bad or not, and live happily ever after. *If you're
into being sure, I suggest you look into purchasing or building an ESR
(equivalent series resistance) meter, as you're guaranteed to run into
this problem in other devices that use electrolytics (motherboards,
TV's, power supplies, monitors, game boxes, router, etc). *I use mine
far too often.

http://www.ludens.cl/Electron/esr/esr.html
http://www.anatekcorp.com/blueesr.htm
http://www.flippers.com/esrktmtr.html (I have this one)
http://www.midwestdevices.com/index.html

More good reading on LCD repair:
http://www.ccl-la.com/blog/index.php/category/monitor-repair/
Note how just about all the failures are electrolytic capacitors.
Here's your Syncmaster 204 page:
http://www.ccl-la.com/blog/index.php/samsung-214t-repair/
Note the they're symptoms include a "dark picture". *Hmmmm...

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558

Could placing a small 12V fan temporarily, at least, in that area be a
diagnostic tool ?

Yes, I considered this. Unfortunately, as I described, the problem is
very random. For example, it has not surfaced in over a week. So by
trying to cool it, I don't know if it's actually helping, or luck.
The same problem applies to the suggestions I've received to replace
the caps outlined on that website. While I'd be happy to do it, I
won't really know if it has helped for a couple months.

One thing I'd really like is to find a trigger for this problem. I
will try heat today. Is there a way to "stress" the monitor's
electronics, to try reproducing the issue? Would changing the image
rapidly have any effect? Should I display a solid color (perhaps
white) on it?

With a reasonably reliable repro procedure (even if it takes hours), I
can then get more info, and attempt to fix it, all while having some
confidence that my changes have either helped or not.