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"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 24 07:05PM +0100 "N_Cook" <diverse@tcp.co.uk> wrote in message news:n0fb26$ld$1@dont-email.me...   > If there is no dusting or latent image on the drum/transfer sheet, when > halting the machine mid-cycle and opening up, then failed corona generator > perhaps   That would be my guess - AFAICR: the laser discharges the static charge on the photoconductive film at the points where no toner should be attracted to.   I think a failed laser would result in a completely black page, maybe the transistor that drives the laser going leaky - but that's in a critical constant current loop, a leaky transistor would probably destroy the laser.

Jeff Liebermann <jeffl@cruzio.com>: Oct 25 12:32AM -0700 >just powdered toner and smear easily. Not so.   >Lots of toner. Still, I took out the cart and shook it around and >reinstalled. No joy.   If it faded like that, I would guess(tm) that you're out of toner. Try a different or new toner cart anyway.   Also, I've seen the shutter mechanism jam or break on the toner cart or at the entrance slot to the laser scanner. Play with the toner cart mechanism and see if the protective shutters are operating normally.   Just for grins, try a test page from the printer, not the computah. If the test page works, look for computer problems.     -- 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

DaveC <not@home.cow>: Oct 25 01:00AM -0700 On 24 Oct 2015, Ian Field wrote   > I think a failed laser would result in a completely black page, maybe the > transistor that drives the laser going leaky - but that's in a critical > constant current loop, a leaky transistor would probably destroy the laser.   Any idea the approx voltage of the corona wire? I could check, but it would be nice to know if it's 300, 600, 1000?   Thanks.

N_Cook <diverse@tcp.co.uk>: Oct 25 08:17AM On 25/10/2015 08:00, DaveC wrote:   > Any idea the approx voltage of the corona wire? I could check, but it would > be nice to know if it's 300, 600, 1000?   > Thanks.   More like 2,000 to 5,000V. The generator is often a selfcontained unit off 28V or so, with just an on/off control line. Flop a 100M resistor to the corona wire and insulated lead out to a neon bulb to frame , in the first instance.

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 25 04:34PM "N_Cook" <diverse@tcp.co.uk> wrote in message news:n0i331$k8r$1@dont-email.me... > 28V or so, with just an on/off control line. Flop a 100M resistor to the > corona wire and insulated lead out to a neon bulb to frame , in the first > instance.   Pretty sure I've seen one at 6kV, most were somewhere around the 5kV mark.   Some older types are pretty sturdy and can give a nasty nip. Unlikely to be as dangerous as microwave oven innards, but I still wouldn't bother sticking my fingers in there!

jurb6006@gmail.com: Oct 24 11:13PM -0700 So now, with the coveted volume two in hand, I see they call the vertical horizontal and the horizontal vertical. The print does depict what I had been reverse engineering. I think on page 7-249.   The vertical circuit does not use a boost cap, switcher or diodes as far as I can tell. Simple transconductance (current) amp run off a ramp.   It has vertical foldover, that is usually caused by not enough voltage peak on retrace. In an old TV it would almost certainly be a bad lytic. But this does not use that type of circuit.   Actually it might be a bit of fun doing this. I have to put leads on the board to test it because it is shielded. What's more, the way it is I have to use insulated wire. Alot of times I have just used solder, but that won't work with this.

Ken Layton <KLayton888@aol.com>: Oct 24 12:33PM -0700 > Cylindrical. Axial leads.   > Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.   It's called a "barreter". It's just a lamp used as a current limiter.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Oct 25 08:39AM +1100 > been shaken out of the originals. But I had no luck finding those > bulbs. I would rather not jump it out. I guess I could and just put a > beefier horn in it.   **Select an appropriate sized Polyswitch™. Cheap, reliable and effective.   -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

"Gareth Magennis" <sound.service@btconnect.com>: Oct 24 10:49PM +0100 "Trevor Wilson" wrote in message news:d92c5nF8av2U3@mid.individual.net...   > been shaken out of the originals. But I had no luck finding those > bulbs. I would rather not jump it out. I guess I could and just put a > beefier horn in it.   **Select an appropriate sized Polyswitch™. Cheap, reliable and effective.           Polyswitches are not compressors.       Gareth.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Oct 25 10:58AM +1100 On 25/10/2015 8:49 AM, Gareth Magennis wrote:   > Polyswitches are not compressors.   **Correct. They're much better. They protect drivers, without significant audible problems (like compression).     -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

"Gareth Magennis" <sound.service@btconnect.com>: Oct 25 01:54AM +0100 "Trevor Wilson" wrote in message news:d92kb7Fa87iU3@mid.individual.net...   On 25/10/2015 8:49 AM, Gareth Magennis wrote:   > Polyswitches are not compressors.   **Correct. They're much better. They protect drivers, without significant audible problems (like compression).             Do you think you would be able to hear such a compression problem?     Gareth.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Oct 25 02:23PM +1100 On 25/10/2015 11:54 AM, Gareth Magennis wrote:   > Do you think you would be able to hear such a compression problem?   **Absolutely. I've proven it, under blind test conditions, to clients who own speakers that are equipped with such things.     -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Phil Allison <pallison49@gmail.com>: Oct 24 09:10PM -0700 Trevor Wilson wrote:   > **Select an appropriate sized Polyswitch(tm). Cheap, reliable and effective.   ** Polyswitches are not a good alternative to low voltage lamps with horn drivers in systems used for sound reinforcement.   Biggest problem is the sudden switch off of the horn and long wait for it to come back on - this is unacceptable to performers or audiences.   OTOH, correctly chosen lamps act immediately - reducing the over power condition to a safe level for the horn driver and then recover almost as fast.   Many active systems use limiters that do the same job.     ... Phil

jurb6006@gmail.com: Oct 24 09:54AM -0700 Somewhat like the people who leave their stereo at flat response. the bass and treble controls are there to be used. Every recording is not perfect and every speaker is not perfect, especially in a real room.   How the shoot these new movies and shows annoys me. Color effects, the blacks are green or whatever. And I know it is them because if you turn the color all the way down you have a good greyscale. Camera angles shifting like a damn toddler had the camera.   And geometry ? Either it is letterboxed, cropped on the sides or overscanning because they haven't gotten their aspect ration shit together.

thekmanrocks@gmail.com: Oct 24 11:40AM -0700 > Somewhat like the people who leave their stereo at flat response. the bass and treble controls are there to be used. Every recording is not perfect and every speaker is not perfect, especially in a real room.   > How the shoot these new movies and shows annoys me. Color effects, the blacks are green or whatever. And I know it is them because if you turn the color all the way down you have a good greyscale. Camera angles shifting like a damn toddler had the camera.   > And geometry ? Either it is letterboxed, cropped on the sides or overscanning because they haven't gotten their aspect ration shit together.   ___ Actually jurb, the default TV settings are like having the bass & treble jacked fully clockwise, or the graphic equalizers set like smileys - middle sliders down, and sliders toward the ends higher and higher.   As far as aspect ratio is concerned, 16:9 or "screen fit" will accommodate most viewing scenarios. I'm really annoyed by those who insist on stretching 4:3(old fashioned TV) pictures to fit their wide-screen HD theater, so J.J. from "Good Times" looks wider than superintendent Bookman. LOL!

stratus46@yahoo.com: Oct 24 11:18AM -0700 On Thursday, October 22, 2015 at 3:05:38 PM UTC-7, Percival P. Cassidy wrote: <snip> > or donate a working monitor to the thrift store/charity shop (whichever > term you use where you live) than simply trash it.   > Perce   Older LCD monitors use CCFL (Cold Cathode Fluorescent Lamps) for backlighting and these wear out like any other lamp. Capacitors also go bad FREQUENTLY. There are 'kits' ($15 to $20) to convert CCFL to LED backlighting and I have successfully converted several monitors to LED but it requires above average knowledge. The panel gets disassembled down to individual layers in the backlighting, possible mechanical mods to accommodate the new power module and getting the 12-30 Volt power source into the new power module.   The monitors I did this to are in rack mount drawers with keyboard and track pad so the time was worth it to salvage these expensive units. For home use that's your call and with 24" units on sale for $100 it may not be worth the time unless you want the 'education'.   G²

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Cydrome Leader <presence@MUNGEpanix.com>: Oct 23 09:36PM > black level enhancer, digital noise re- > duction, etc.) Backlight(if it's a LED or > LCD) is all the way up, etc.   The problem I see with most LCDs is the color temp due to the LED backlighting. Everything is way too cold (blue). Except for that, just peek in a bar with multiple TVs, they're not perfectly matched, but far closer than in the days of CRTs or plasma stuff. There's no phosphors or electron guns to weaken at different rates.   The drift (in everything) in the plasma airport arrival/departure screens was pretty amazing too, even if you cut some slack for those displays having been used in the worst possible conditions.

thekmanrocks@gmail.com: Oct 23 02:56PM -0700 > black level enhancer, digital noise re- > duction, etc.) Backlight(if it's a LED or > LCD) is all the way up, etc.   The problem I see with most LCDs is the color temp due to the LED backlighting. Everything is way too cold (blue). Except for that, just peek in a bar with multiple TVs, they're not perfectly matched, but far closer than in the days of CRTs or plasma stuff. There's no phosphors or electron guns to weaken at different rates.   The drift (in everything) in the plasma airport arrival/departure screens was pretty amazing too, even if you cut some slack for those displays having been used in the worst possible conditions. "     Cyndrome: The reason you are seeing those "way too cold" color temperatures is because in the advance settings the highest/bluest color temperature is set by default!   As for the creature cantina scene - of course the TVs in there are not matched: different mfgs have different factory default settings; but what those settings do have in common is: they were selected to make their product stand out on a sales floor - NOT to be watched for any appreciable length of time.   Bet you a five-legged horse that if even just the user controls(color temp set to neutral instead of high, backlight on LEDs set in half, and the bright, contrast, color, sharpness all set via test DVD) you'd be hard pressed to see any difference between sets at opposite ends of the bar - assuming they are all tuned to the same game, as they likely all will next week for the series.   What more can I do to convince you guys that OOB (out of the box) settings are no good for a consumer display, or for your eyes? In fact, I find the factory "BUY ME, BUY ME!" settings on modern flat panel TVs are worse than the factory defaults on any old CRT tube I've EVER seen.

Cydrome Leader <presence@MUNGEpanix.com>: Oct 23 10:41PM > The reason you are seeing those "way too cold" color > temperatures is because in the advance settings the > highest/bluest color temperature is set by default!   The backlights themselves are really just too blue. This is a problem of sorts when laptops went from CCFL backlighting to LEDs- the color temp went way too high. It can probably be adjusted, somehow, but it doesn't help the color is just wrong to start with.   > have in common is: they were selected to make their > product stand out on a sales floor - NOT to be watched > for any appreciable length of time.   they all match pretty much, even in a place like best buy. All those cheapo LCD panels are probably coming out of the same 3 plants. Nobody cares about special phosphors or dot patterns or shadow masks like in CRT days. Sure there's cheap and expensive display panels, but they just don't seem to vary all that much otherwise.   > Bet you a five-legged horse that if even just the user > controls(color temp set to neutral instead of high, > backlight on LEDs set in half, and the bright, contrast,   Even half brightness, they're still too blue too look natural.   > "BUY ME, BUY ME!" settings on modern flat panel > TVs are worse than the factory defaults on any old > CRT tube I've EVER seen.   I'll restate what I said before- LCDs lack the color and brightness variations that affected CRTs. Default settings have always been and are still pretty horrible, but at least these days if you buy a demo LCD TV, it's safe to say the thing isn't already worn out like a CRT would have been trying to dazzle customers with every setting turned way up.   For viewing at home, I use an Epson projector that seems to have 3 CCDs and the starndard arc lamp. I forgot what the default factory settings were, but they were garish and made even the OSD menu setup hard to look at. It had to be something like high brightness, 14k color temp and no doubt some sort of vivid control cranked way up. I did not bother with any real calibration, but made sure white looked white and the brightness was reduced so that set so that "black" on the screen looked black, even though the screen itself is white.   How do you suggest adjusting a projection system?

"Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 23 06:51PM -0400 Cydrome Leader wrote: > reduced so that set so that "black" on the screen looked black, even > though the screen itself is white.   > How do you suggest adjusting a projection system?       WHite LEDs are actually blue, with a phosphor to make it into something near white light. They fail in that attempt.

thekmanrocks@gmail.com: Oct 23 03:58PM -0700 Cyndrome wrote: "How do you suggest adjusting a projection system? "   A Blu-Ray Digital Video Essentials disc *should* produce the same results for your projector as it would for any flat panel HDTV. Just follow all instructions.

jurb6006@gmail.com: Oct 23 08:56PM -0700 >peek in a bar with multiple TVs, they're not perfectly matched, but >far >closer than in the days of CRTs or plasma stuff. There's no >phosphors or >electron guns to weaken at different rates."   Most of them now have user color temperature adjustments. That will be at the highest setting when it leaves the factory.   The LEDS are chosen for the high blue output because to use the display to lower the color temperature is much cheaper than to raise it. In terms of brightness. And it does not react as well as CRTs did. But in both, if you DO want higher color temperature you need to boost the blue. Reducing the red and green is not the right way to do it.

thekmanrocks@gmail.com: Oct 24 03:58AM -0700 jurb...@gmail.com wrote: "Most of them now have user color temperature adjustments. That will be at the highest setting when it leaves the factory.   ^Correck!^ :)     Folks I have come to the conclusion that the majority of people don't even know these new-fangled panels HAVE settings or a menu under which settings can be found. I'm dead serious. And they live with their TVs looking like cartoons not knowing that they are getting only 5% of out of their investment's potential.   A damned SHAME, as is their attitude when I offer to make it better:   "It's fine the way it is"   "It's brand new; that's the way it's supposed to look."   "LEAVE IT ALONE"....     And that's the toughest part of being a calibrator - or at least, someone who knows better.

jurb6006@gmail.com: Oct 23 09:07PM -0700 Cylindrical. Axial leads.   Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.

Chris Jones <lugnut808@spam.yahoo.com>: Oct 24 04:13PM +1100 > Cylindrical. Axial leads.   > Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.   Possibly an automotive parts store, depending on what voltage rating was originally fitted. Some trailer lights use them. If it was not 12V or 24V then you'd have to look elsewhere.

gregz <zekor@comcast.net>: Oct 24 06:35AM > Ordered caps for a speaker crossover because the leads had literally been > shaken out of the originals. But I had no luck finding those bulbs. I > would rather not jump it out. I guess I could and just put a beefier horn in it.   I assume they are burnt out. You could try a 12 volt lamp with no more than 1-2 ohms cold resistance. You could also use a tweeter protector PTC resistor. I assume they were overdriven.   Greg

mroberds@att.net: Oct 24 08:56AM > Cylindrical. Axial leads.   Fuse lamp? It doesn't really have leads, but it's the same size as a 3AG fuse.   http://www.allelectronics.com/make-a-store/category/320300/lamps/fuse-lamps/1.html   Otherwise, maybe something like a 561, 563, or 211-2 automotive lamp. They have wire hoops on the ends. The 561 and 211-2 are 12.8 V, 0.97 A nominal; 563 is 13.5 V, 0.52 A nominal.   http://www.walmart.com/ip/Sylvania-211-2-Long-Life-Incandescent-Mini-Bulb/16913643   > But I had no luck finding those bulbs.   Do you still have a working lamp? If so, carefully put a few volts on it, measure the current, go up a volt, measure the current, etc, and pick something close to replace it.   Standard disclaimers apply: I don't get money or other consideration from any companies mentioned.   Matt Roberds

"Gareth Magennis" <sound.service@btconnect.com>: Oct 24 10:16AM +0100 wrote in message news:a1a81484-bae7-4241-884c-2a5667e839d6@googlegroups.com...   Cylindrical. Axial leads.   Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.           http://www.parts-express.com/speaker-crossover-tweeter-protector-lamp--260-231   http://www.amazon.com/Eminence-PX-Replacement-Protection-Crossover/dp/B000BBOVS0       Gareth.

"Gareth Magennis" <sound.service@btconnect.com>: Oct 24 11:11AM +0100 wrote in message news:a1a81484-bae7-4241-884c-2a5667e839d6@googlegroups.com...   Cylindrical. Axial leads.   Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.           JBL also do one with flying leads.   https://www.bluearan.co.uk/index.php?id=JBLSK3BULB       Gareth.

DaveC <not@home.cow>: Oct 23 11:53PM -0700 Brother HL-5170DN   The next-to-last page I printed was faded—very pale text. The next one was blank, white.     If it was the fuser I know I'd see the text on the page but it would be just powdered toner and smear easily. Not so.   Lots of toner. Still, I took out the cart and shook it around and reinstalled. No joy.   Where to start looking?   Thanks.

N_Cook <diverse@tcp.co.uk>: Oct 24 08:15AM +0100 On 24/10/2015 07:53, DaveC wrote: > reinstalled. No joy.   > Where to start looking?   > Thanks.   If there is no dusting or latent image on the drum/transfer sheet, when halting the machine mid-cycle and opening up, then failed corona generator perhaps

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"pfjw@aol.com" <pfjw@aol.com>: Oct 22 11:17AM -0700 > did notice that you seem to think that calibration is some- > thing that must be done periodically(every year or two for > example).   No, I stated that the settings, once done, were remarkably stable, even through power-failures. I did have to re-calibrate after a 6-day failure (Hurricane Sandy), but not for failures as long as several hours. > You then recalibrate that input for that device. I tell > all of my customers this: that their calibrated settings > should not drift for at least a decade. :)   I have not experienced that need - we switched about 2 years ago from a basic DVD player to a compatible, self-upgrading blue-ray DVD with no visible need to re-calibrate - and the software with the kit verified this.     > "That would be my take on the use of that term-of-art for our particular unit. "   > Not sure what you mean by "term of art". > Please elaborate.   Term-of-Art: A word, combination of words or phrase specific to one thing that is used outside of its common definition. To me the term "calibrate" is specific to measuring devices, meters, tube testers, signal generators, rotameters, gauges and so forth that are set to a specific standard such that measurements from them can be trusted. I would not generally consider arbitrary settings based, in part, on taste rather than independent standards, would be any sort of 'calibration'. At least, again, as I understand and would normally use the term. There are those that prefer bright settings and cartoonish colors. De gustibus et coloribus non est disputandum. Quidquid latine dictum sit, altum videtur.   Peter Wieck Melrose Park, PA

thekmanrocks@gmail.com: Oct 22 11:57AM -0700 "me the term "calibrate" is specific to measuring devices, meters, tube testers, signal generators, rotameters, gauges and so forth that are set to a specific standard."   Likewise! DVD test patterns also count, as long as one follows instructions on what to look for when the specific control(brightness, contrast) is adjusted optimally.   I still sense a lot of skepticism in your responses regarding display ALIGNMENT - there, I just found a new name for it that makes sense! :)

whit3rd <whit3rd@gmail.com>: Oct 22 12:14PM -0700 > I've worked in broadcast and post production since 1976 and calibrated many monitors, some used for THX film transfers and verified by their tech. Calibration was mandatory with CRT monitors and on a regular basis. The new TVs are amazingly consistent and I find no desire and certainly no need to 'tweak' them. In fact, unless you're very qualified I would not allow you to touch my TV.   Generally, there's no calibration in an LCD TV that requires touching. Digital signal, not affected by movable magnets or variable resistors. If you use your TV for a computer monitor, though, and have a color printer: you ought to calibrate the video card or the printer driver so that the color prints produce the same colors as the screen display. Getting the correspondence right is important for artistic uses, and requires (1) controlling reflected light off the screen (2) getting as much color gamut and contrast on the screen as on the paper (not easy, might require special paper) (3) controlling the illumination light when viewing printed material (4) adjusting R, G, B zero points (5) adjusting R, G, B brightnesses (6) adjusting for any nonlinearity (usually called 'gamma correction') for R, G, B (7) readjusting from time to time, as papers, inks, phosphors may age.   It can be hard to find and rectify any adjustments. Or, it can be easy - Apple made a ColorSync monitor with internal light sensors that did recalibration in a few seconds if you pressed the front-panel button).

"pfjw@aol.com" <pfjw@aol.com>: Oct 22 12:21PM -0700 > responses regarding display ALIGNMENT - > there, I just found a new name for it that > makes sense! :)   Mpffff..... Here we go again....   Alignment: My primary hobby is vintage radio restoration and repair, so "alignment" is a very specific term. Shifting that term from rF to Visual alignment is not a stretch, just not what leaped to mind when I read your assignment of this term to that process. Telescope people call it "collimation", musicians call it "tuning" but they are all forms of aligning some sort of information for greater accuracy/clarity.   Peter Wieck Melrose Park, PA

stratus46@yahoo.com: Oct 22 03:07PM -0700 > So if I understand you correctly, If you were to buy a brand new > flat panel set, connect it all up and start watching it, you would > leave the user menu settings all in their factory positions?   No. That looked bad because it was in 'store demo' mode. I don't consider the 'user adjustments' namely brightness, contrast, saturation (color), back light and sharpness to fall into the 'calibration' category. Calibration to me involves individual RGB gain, lift and gamma. These were finicky with CRTs but don't need much if any tweaking with LED lit LCD sets.   G²

thekmanrocks@gmail.com: Oct 22 03:09PM -0700 whit3rd wrote: "Generally, there's no calibration in an LCD TV that requires touching. Digital signal, not affected by movable magnets or variable resistors. "   So I will ask you the same question: If you bought and unboxed a brand new flat panel TV for your home, would you leave the user and semi-advanced settings in their factory mode? Have you actually seen a TV(any TV, CRT, Plasma, LED, etc) in its factory defaults?     Again, I'm talking about the SETTINGS, not the broadcast or cable signal fed into the back of it. And no, for the purposes of this dis- cussion, there is no concern of "drift" because we are in the micro- circuit digital realm.

thekmanrocks@gmail.com: Oct 22 06:38PM -0700 Your silence on this subject speaks volumes. Out of the box, a new con- sumer grade TV is like staring at the midday sun for a half-hour to an hour.     It is typically set to "Vivid" or "Dynamic" mode, which is useful only for display in a retail sales floor environment. Contrast, color and sharpness are cranked, color temperature is skewed to 10,000+Kelvin - ultra blue, and every so-called "enhancer" under advanced settings is checked(skin tone enhancer, black level enhancer, digital noise re- duction, etc.) Backlight(if it's a LED or LCD) is all the way up, etc.     Just taking it out of Vivid, and turning off all that CRAP in the advance menu gets you from some vague location in the South Bronx INTO Yankee Stadium, in terms of accuracy! The professional calibration we discussed here will take you from a seat somewhere in the right- field upper deck right onto home plate.     And there are no "personal preferences" when it comes to picture settings - only one right combination of basic and advanced controls, and 1,000 possible WRONG combinations.     it's your choice: Stare at the sun every night during the 6 o'clock news, or see what the host and the world through the cameras really looks like.

isw <isw@witzend.com>: Oct 22 09:14PM -0700 In article <208f2024-220b-42d4-a4f6-8d2decf4bd64@googlegroups.com>, > (1) controlling reflected light off the screen > (2) getting as much color gamut and contrast on the screen as on the paper > (not easy, might require special paper)   I'm pretty sure it's the other way around -- any decent screen will have a much broader gamut than any subtractive color process (i.e. any sort of image printed on paper). Same with contrast ratio -- the screen wins by an order of magnitude or better.   Isaac

Jon Elson <jmelson@wustl.edu>: Oct 22 05:06PM -0500 John Larkin wrote:     >>middle-of-the-road ESR that makes 7800s happy.   > My favorite cheap "MDO" regulator, the LM1117, loves a 10 uF tantalum > on its output. I've had excellent results using two 22uF aluminum electrolytics, one on the input, one on the output, of ZLDO1117 regulators. I've built several hundred devices with that setup, to produce 1.2 to 3.3 V supplies for FPGAs.   Jon

Jon Elson <jmelson@wustl.edu>: Oct 22 05:08PM -0500 rickman wrote:       > Is it about clearing damage or just to show the added resistance > prevented the failure? I found the story a bit hard to follow.   I believe he set up the production line to ramp up the supply voltage with current limiting on EVERY board as it comes out of the reflow oven.   Jon

makolber@yahoo.com: Oct 22 11:15AM -0700 > > Probe around with a digital storage scope to see what happens > > on power up.   > I neither own nor have access to any kind of scope.   that makes it difficult   I have seen descriptions of replacing the CFL backlights with white LED strips. That would make a nice project.   Mark

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 22 10:14PM +0100 "Percival P. Cassidy" <Nobody@NotMyISP.net> wrote in message news:d8psurF43noU1@mid.individual.net... > discolored PC board.   > Since the PC board itself showed signs of overheating, I thought it better > to look for a replacement power-supply module   Sadly - heat discoloured PCBs isn't as rare as it ought to be.     The trick is to make a judgment as to whether there is potentially a fire risk. In any case - a replacement from the original source will probably go the same way.   If the problem is on the CCFL inverter board - a company called HR in Spain does pattern spares.   They were originally well known for high quality pattern replacement horizontal output transformers for CRT displays.

"Percival P. Cassidy" <Nobody@NotMyISP.net>: Oct 22 06:05PM -0400 On 10/22/2015 05:14 PM, Ian Field wrote:   > Spain does pattern spares.   > They were originally well known for high quality pattern replacement > horizontal output transformers for CRT displays.   I don't want to put much more money or time into this project: I already have a replacement for our own use but would rather keep it as a spare or donate a working monitor to the thrift store/charity shop (whichever term you use where you live) than simply trash it.   Perce

Jon Elson <jmelson@wustl.edu>: Oct 22 02:38PM -0500 Ian Field wrote:   > hope the heat would desiccate any lingering residues. It seemed OK for a > while, but soon became apparent that the buttons had a life of their own > in humid weather. The Dell monitor I had this problem with had 4 buttons. The power button was fine, the other 3 had trouble at different times. They have a small surface-mount capacitor on the back across each button switch. The switches appeared to be well-sealed, but the soda stuff gut under the caps, ate some of the PC board, and caused lingering conduction. So, I removed all the caps, severely scrubbed the PC board with solvent and a toothbrush, and soldered on, I think, 1000 pF caps where the bad ones were. This has solved the problem.   Your results sound EXACTLY like what mine was doing, and I had to remove the caps, clean and replace with new caps. Most likely, it would work fine without the caps. (I have quite a big stash of SMT parts as I assemble PC boards.)   If the switches are not sealed, then they are almost certainly full of sticky, conductive gunk, and would have to be replaced.   Jon

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 22 08:44PM +0100 "Jon Elson" <jmelson@wustl.edu> wrote in message news:I6CdnS5l7otOp7TLnZ2dnUU7-audnZ2d@giganews.com... > caps, clean and replace with new caps. Most likely, it would work fine > without the caps. (I have quite a big stash of SMT parts as I assemble PC > boards.)   AFAICR: there were no other components on the front PCB.   Finding the abandoned Dell came in just right, I'm not short of monitors over all - so getting around to working on the faulty one could take a while.

"Ian Field" <gangprobing.alien@ntlworld.com>: Oct 22 05:47PM +0100 <ggherold@gmail.com> wrote in message news:fc686851-ae1f-4f2d-987c-863570a8b631@googlegroups.com... > control.   > (I like the Cockroft chain because it's not all that hard to understand.)   > Any thoughts?     You could probably get away with the chopper transformer out of the SMPSU in a ser top box like a DVB-T type thing.   Using the transformer back to front, you can get pretty decent HT with a simple blocking oscillator on what used to be the secondary.   Or you could go for a capacitor discharge unit. Of course you need another chopper transformer to make the inverter. About 250 - 350V is good enough for the intermediate voltage, you can make a simple relaxation oscillator with 2 or more series neon bulbs and a capacitor to fire the SCR.   Years ago I made a pocket disco strobe along those lines, it used the xenon tube from an old camera and run off 4x AA Ni-Cd cells.

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