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N_Cook <diverse@tcp.co.uk>: Feb 08 02:35PM A talk given by a local expert on LC devices, Matthew Proctor, Southampton University, from the Q&A after the talk, my query   I've brought along , what I often see in repairing electronic stuff, black bleeding within a 7-segment LC display. All I know is the problem seems to develop from being excessively cold or hot and I'm assuming the 2 glass plates cleave apart , then the LC bleeds across but I've never found out why the numbers fail to register anything although there is LC everywhere? All such LC displays have polarizors in them , light going in through one and out through another . If we remove the LC from the situation entirely all you get is something that light cannot go through. You can only get this birefringent effect with 2 glass plates , normally coated with some kind of plastic , stick them close to one another , the gap can go up to about 0.5mm if your lucky. In a TV they are usually about 5 micron or so. As you say , in this numeric LC display, the plates have moved apart slightly and the LC is no longer ordered properly. You get something that is cloudy again, its not birefringent. You have small area htere where the LC is lined up but lots of these microdomains where there is no order as to the direction of the domains and the light is scattered . The LC is no longer being aligned by the polymer and what you have instead is something that is not doing anything significant to the light and you have 2 polarizors and so black. I forgot to say how thick this layer is . It has to be carefully controlled depending on what colour you want to come through. If you change the thickness of that layer a bit, then you'll change the colour of the light that comes through it. If you poke a LCD with a finger and see rainbow fringing that is what is happening there, you are flexing the display, changing the thickness , and changing the wavelength of light its letting through, as you have RG and B light behind it. With large flat pieces of glass on laptop screens , how can they guarantee absolutely rigorous separation, until you poke your finger at it, anyway, it seems impossible? They are very very good engineers, very good at what they do. The things we make in the lab , tend to sag in the middle , so about 2 microns thinner than at the edges. Something we ar einvestigating as its often ignored in hte literature. Really thin, tiny electrodes , so carefully designed to get these things working. Generally on new monitors these days, you will not get a single pixel breaking for years.

Leif Neland <leif@neland.dk>: Feb 08 01:52PM +0100 > TV sucks in this country. they do not have their HDTVC shit together. Half > the time it is overscanned and you lose half the picture or you get a 20" > picture on a 32" screen.   I also hate when they have a 16:9 source, then put it into a 4:3 frame with their station logo at the top, and dark gray bars at top and bottom. Then when it is wiewed on a 16:9 screen, there is also black bars at the sides.   Often I can't zoom to get the original 16:9 to fit the entire screen, because of subtitles burned into the video stream in the lower dark gray bar.   (   -- Je suis Charlie

Pat <pat@nospam.us>: Feb 08 08:49AM -0500 On Sun, 08 Feb 2015 13:52:52 +0100, Leif Neland <leif@neland.dk> wrote:   >because of subtitles burned into the video stream in the lower dark >gray bar.   >( I usually see that sort of thing when the original material is SD or they are sending it over a low bandwidth channel. In those cases, it makes sense to me because at least it shows the material in the correct aspect ratio. An example here (US) is the local PBS station. They run an HD main channel plus a bunch of SD subchannels. When they put an HD show on one of the subchannels, it gets displayed at a reduced size in the middle of the screen. They put logos around the edge because they are static and use almost no bandwidth, but the show itself can't be shown full size with the limited bandwidth available on the subchannel.

senderj@hotmail.com: Feb 07 04:32PM -0800 I have a Panasonic NN-GS597M microwave. When using its microwave heating function, it stops after 4 seconds regardless of the setting is H/M/L. In this 4 seconds, there is a slight "tic tic" sound near the a/c rectifier and the large transformer of the inverter (they seat close to each other). I managed to find an inverter board and replaced it, but didn't solve the problem. So it must be something else that cause the problem.   The rectifier board is just simple R, C, varistor and self recovering fuse, which are unlikely to have any problem. For magnetron, I've measured the resistance of the 2 leads. With my DMM at 200ohm it reads 0.3. Each lead is open to the case of the ovan. So I think the magnetron is ok. So what else can I check to resolve the problem. Please help.   NB. http://www.repairfaq.org/sam/micfaq.htm is where I learn the above, in case it can help others.

sender jones <senderj@hotmail.com>: Feb 07 04:48PM -0800 One more point, during this 4 seconds, the ovan is noisy as usual. But after it failed, it is quiet but the cooling fan is still turning.

c4urs11 <c4urs11@domain.hidden>: Feb 08 09:33AM On Sat, 07 Feb 2015 16:48:25 -0800, sender jones wrote:   > One more point, during this 4 seconds, the ovan is noisy as usual. > But after it failed, it is quiet but the cooling fan is still turning.   Can this help, disregarding its fun typos? http://ask.metafilter.com/259488/Possessed-mircowave     Cheers!

captainvideo462009@gmail.com: Feb 07 06:01PM -0800 On Thursday, October 17, 2013 at 7:55:39 PM UTC-4, Dan wrote: > trying to sell fuses, not any giving how to read the ratings.   > TIA   > Dan   Jeff You mentioned that you have a number of different breakers fitted with clip leads for testing before you install an actual fuse. I hate to repeatedly blow fuses too, but doesn't that increase the time it takes for the circuit to open, thus subjecting the equipment to possible further harm? Lenny

Jeff Liebermann <jeffl@cruzio.com>: Feb 07 09:58PM -0800 On Sat, 7 Feb 2015 18:01:09 -0800 (PST), captainvideo462009@gmail.com wrote:   >Jeff >You mentioned that you have a number of different breakers fitted >with clip leads for testing before you install an actual fuse.   Yep.   >I hate to repeatedly blow fuses too, but doesn't that increase >the time it takes for the circuit to open, thus subjecting >the equipment to possible further harm? Lenny   Chuckle. That would be like comparing the old screw in electric panel fuse with the more modern circuit breakers. Actually, the magentic circuit breaker is faster than the thermal fuse up to about 2x rated current.   However, it doesn't matter. If the power supply is shorted, blowing the circuit breaker a bit late isn't going to make much difference as the power supply is already fried. Whatever is blown or shorted will probably protect the rest of the circuitry. However, if everything is working correctly, the circuit breaker won't trip so it make no difference how fast or slow it opens.   Where it might get a bit sticky is a fairly low resistance short across the power supply output. That won't draw enough current for a instanteous breaker trip and might cook a few devices or traces between the power supply and the low resistance short. It's a definite risk, which I'll gladly take, because I haven't seem much of that. Most commonly, it has happened when I stupidly install electrolytic caps in backwards, which hopefully will not become chronic or epidemic.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

"hrhofmann@sbcglobal.net" <hrhofmann@sbcglobal.net>: Feb 07 08:18PM -0800 What the OP wants is a simple pushbutton switch, like a doorbell switch.

Adrian Caspersz <email@here.invalid>: Feb 07 08:23PM >> hiiii frnd im new in this group im need schematic diagram 10203-1 b560 laptop   > The brand might help, but really you don't usually get schematics for computers. Fact is, the way they are, all you can do is change regulators and capacitors. Then some of them (in the words of a mobo manual I read years agho) "hang permanently when the errors introduced by dirty power corrupts the BIOS past being able to flash. If it won't boot it won't flash. One of mine locked the harddirve in error, but that model harddrive was very susceptable to that problem. (WD1600BEVT, don't buy one)   > You would be better off posting the problem you're having with it.   His machine is a Lenovo.   There are a few dodgy websites in Thailand / Malaysia / Vietnam that host free recent laptop schematics (pinched from the factory?). Takes a bit of googling.   Start with the word kythuatvitinh and don't do it from a Windows machine.   -- Adrian C

jurb6006@gmail.com: Feb 07 09:42AM -0800 >"" Well, I didn't think anyone would do something so stupid. "   Well, over here in the states I have come to expect shit like that.   Now the warranty thing, these are stock units. They play them, which is alright usually as the instruments and amps get tested.   Of course some tests cannot be passed. Lik the last time someone told me to go fuck myself. I know I can't do that. Don't even know anyone who can.

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