LCD Desktop Monitor Fading to White, then Black
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From: Jeff Liebermann on 3 May 2010 01:11 On Mon, 3 May 2010 05:34:56 +0100, Mike Tomlinson <mike(a)jasper.org.uk> wrote: >In article <h9est5dts76ogd6n7fktt0rrk4o4a79iud(a)4ax.com>, Jeff Liebermann ><jeffl(a)cruzio.com> writes > >>Incidentally, having two identical monitors is a bad idea. Sympathetic >>failure and contagious failure modes has been known to propagate >>between the bad monitor and the good. > >Yeah, I know. Just had two Iiyama 20" TFTs (used side by side with a >spanned desktop) fail on me. Expensive lesson. That might be a different problem. The warranty timer chip found in most electronic devices may have been triggered. The manufacturer sets the warranty countdown timer to induce a failure immediately after the warranty expires. When the power supply blows up, and produces a continuous clicking sound, I tell the customer that's the warranty timer still running. <http://pinktentacle.com/2010/01/secret-sony-timer-kills-products-after-warranty/> -- Jeff Liebermann jeffl(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
From: N_Cook on 3 May 2010 04:01 Jeff Liebermann <jeffl(a)cruzio.com> wrote in message news:9edst5drns9dhhvmbonl5gds2v615pn9bm(a)4ax.com... > On Sun, 2 May 2010 17:53:14 -0700 (PDT), saber850 <saber850(a)yahoo.com> > wrote: > > >On May 2, 5:10 pm, Jeff Liebermann <je...(a)cruzio.com> 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 jeffl(a)cruzio.com > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://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 ?
From: William Sommerwerck on 3 May 2010 07:37 > Incidentally, having two identical monitors is a bad idea. > Sympathetic failure and contagious failure modes has been > known to propagate between the bad monitor and the good. > I would keep them apart just to be safe. Uva uvam videndo varia fit, right?
From: Adrian C on 3 May 2010 10:37 On 03/05/2010 03:50, Jeff Liebermann wrote: > Incidentally, having two identical monitors is a bad idea. Sympathetic > failure and contagious failure modes has been known to propagate > between the bad monitor and the good. It's not only that. There is a grating feeling when two otherwise identical items have one that shows signs of minor inferiority. It's a sick child, something that is crying out for some attention. Ye feel you should be doing something about the one that is failing, but the affliction is so slight that technically it's not a worthwhile process of either taking the cover off or approaching the service agent with complaints. However, that feeling is however a stress to be remembered and eventually dealt with as with all the other stresses one unfortunately collects. Now, if you only had one of the item and that fault was so minor, you'd probably be not so aware of the problem, and certainly not so aware of the stress ... Life is simpler. I'm going to disconnect one of my stereo speakers and live with mono. ;-) -- Adrian C
From: saber850 on 3 May 2010 11:07
On May 2, 10:46 pm, Jeff Liebermann <je...(a)cruzio.com> wrote: > On Sun, 2 May 2010 17:53:14 -0700 (PDT), saber850 <saber...(a)yahoo.com> > wrote: > > >On May 2, 5:10 pm, Jeff Liebermann <je...(a)cruzio.com> 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 je...(a)cruzio.com > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558 Very helpful, thanks. |