A little help with inductor markings? - Page 1
Forum section: electronics / projects

author: starhawk
author_rank: Regular Contributor
timestamp: June 05, 2021, 01:22:12 am
content: I'm looking at an inductor on a motherboard that I want to salvage and repurpose for a project. It's a surface mount type, looks like it's a ceramic block with two metal tabs. It has three lines of text - two three-digit numbers, and a set of three letters.100631BTCI know the first line tells that it's a 10 MicroHenry (10μH) inductor. But I don't know what the other two lines mean -- although what Google suggests for the bottom line seems a bit unlikely, however predictablegood for a chuckle!Can someone help me decode this?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 05, 2021, 04:26:53 am
content: 631 might be a production date, likely 2006 (or 2016 or 1996 or some decade), 31st week. BTC is likely the manufacturer's mark, which doesn't ring any bells so you'd have to look through probably Chinese OEMs to find anything.The relevant ratings are: DC resistance, maximum current (thermal), saturation current, impedance vs. frequency, and core loss.DCR you can measure with a milliohmmeter, if you like.DC current you could also test, typically for a 40°C temp rise (at thermal equilibrium in standard conditions, say, mounted on a horizontal PCB in still air, waiting a few minutes to stabilize). You might need a few amperes to complete the test; pretty available.The rest require some means of testing the impedance or reactance. If you don't have the tools to do that (or don't need to do that!), you're just as well off assuming it's an inductor of normal design -- find similar parts, of the same dimensions, in distributor catalogs, and you'll probably get very close.As for doing the measurements, if you're curious:If you have a signal generator and oscilloscope, you can get some idea of inductance, Q factor, and saturation if you can set up a test fixture for it. A typical method is setting up an impedance divider with a series resistor at the top, and a resonant tank at the bottom. The inductor is paralleled with a known-good capacitor (such as PP film or C0G ceramic), and the input frequency is adjusted for maximum output voltage (resonance). The divider ratio gives resistance (and thus Q factor), while the frequency and capacitance give inductance.https://www.seventransistorlabs.com/Calc/RLC.htmlThis is most helpful for identifying unmarked inductors, and testing your own to verify they're the value they're supposed to be.For saturation, typically you'll use a much larger inductor to feed DC into the DUT, so that it acts in parallel, and has little effect due to its higher value. Do the same test as above, and call it when the bias current causes inductance to drop by 30% or so.If you do the impedance test a few frequencies (range of capacitor values, with suitable resistors to get good confidence in the measurement), you can get some idea of how L and Q vary with frequency. This is just a sampling of points, but if the component is well behaved (likely), you can extrapolate that to a whole curve like this:https://www.seventransistorlabs.com/Calc/Coilcraft1.html(I... don't expect you to dive in and curve-fit your components, or understand the meat of what's on this page, I'm really just using it as a convenient illustration of impedance plots. But that is exactly what you can use such data to do, if you need a model this accurate.)If your signal generator has enough range, you may also be able to test the inductor's self-resonant frequency. This is the peak on the impedance curve. It's typically a few kohms, so it's a bit tricky to get a good measurement at high frequencies (~10s MHz) while avoiding the effects of stray capacitance (which dominates over other stray effects, when impedances are higher than a hundred ohms or so).The gold standard method is to use a vector analyzer, which used to be an incredibly specialized bit of kit, but is rather accessible nowadays with the NanoVNA and such. This can sweep frequency smoothly over a wide range, while measuring full complex impedances, so is a perfect fit for measuring reactive components like this.And so, that covers all the way from plain old supply filters and switching circuits, to full-ass radio frequency circuitry.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 05, 2021, 06:22:04 am
content: WOW that is way more than I expected. Thanks!I won't be able to use most of that tho. Sorry. I guess I should explain myself... why I salvage parts (and need to -- this is not the first time!), why my threads always say "hey, don't tell me to go buy 'x'" etc. Forgive me, please, for the VERY long response!I have a couple disorders and conditions that, in this day and age, are yawn-inducingly common, but they hit me in bizarre ways, and the period I was born in means that as I was growing up, the teachers in the lowest grades of Grade School were getting their first taste of folks properly diagnosed with the sort of stuff I have... Asperger's Syndrome and ADD. I was one of the first ten kids, from what I was told, that the autism therapy/etc group TEACCH diagnosed here in North Carolina (USA) in the mid-1990s. (Supposedly I was #4. These numbers are not verified.) They were doing almost *exclusively* diagnosis in those days because they were in a "wait, how the freak many of these kids ARE there?!" phase lol. I would have been somewhere between six and nine at the time.I also have, surrounding that, a bunch of weird disorders/conditions that I don't have formal names for -- nobody's given me them, and I'm both habitually bad at Google searches and kind of medicinally stupid, in the specific sense that a lot of stuff you find out at the doctor's office has to be explained to me in unusually small words even nowadays. As a result of all of this, I'm pretty good at tech and such but I get a C- in adulting. Sure, I live by myself and can pay bills and such, but my ability to organize my stuff is basically that of FAT32 with no defrag function. One or another of those head conditions (the Asperger's tends to get the blame, accurately or otherwise) screws with my motivational sense, so unpleasant tasks tend to get painfully close to due (or painfully *over*due) before I tackle them, because I literally don't have any sort of compulsion to handle them, even when I know, on an intellectual level, it's gonna bite my rear if I don't deal with it soon. Etc.Further, although I'm an artist, a writer (and -- hopefully -- a budding novelist), a computer nerd, and an electronics hobbyist, amongst other things -- each of those comes to me in ways that make them annoyingly useless in terms of job prospects.While I'm good with computer *hardware*, I can only sort of fumble about, programming-wise, with BASIC -- C and its variants have proved themselves GLORIOUSLY incompatible with my head multiple times over. If I stare at a lump of eg Arduino code long enough (invariably, multiple hours), I can eventually sort of reason through it enough to change a value here or take out a few lines there and more-or-less make it do the slightly different thing I need, although it will be sinfully clumsy. Anything more than that requires, erm, professional help in one way or another. My comprehension of networking largely consists of ways in which a LAN cable can properly be physically interfaced with a router. I can assemble hardware, and often in quite creative forms and shapes, but I have a profoundly odd sense of aesthetic, and I've been known to argue with others over specs and look because I quite easily get lost in my own head. Not to mention I can't troubleshoot to save my freaking life lol.Most of my electronics hobbyist work can be summed up in the simple phrase, "it doesn't work and I don't know why" -- although I heartily admit that this is largely because I have a habit, lacking proper test equipment that a professional lab would have, of building the whole thing at once and not being able to troubleshoot it when it doesn't work hardly at all.Writing and drawing is nice when I can get my autistic hyperfocus on -- I tend to 'focus' (ha!) more in the ADD tradition of a squirrel on the last day of autumn, hunting down that one last acorn before sundown, but with the philosophy in simultaneous action that everything that moves, even a leaf in the wind, deserves its moment of attention -- but writing only happens, really, when that muse comes to me. I can't do it on command unless you want word poo... and my art ability dries up and blows away when it thinks it's done for work.So I draw Disability, because I don't have a hope in heck of EVER holding down a 9-to-5 for three consecutive days. $1100 is great but it has to last a month... the fact that that sum of money puts me in the lower echelons of royalty, practically, as such things go... let's just leave it at "that leaves me with mixed feelings". This is not a forum for PoliSci or socioeconomics discussions, and I'd need to make a rather in-depth dive into each of those subjects, to explain both how they affect me and my life, and how I feel about it all, in proper form. But that would also likely ruffle far too many feathers, and (again) this isn't the place anyways. So we'll not do that here. Suffice to say that, although I do the best that I can with what I can, cooking my own food is for the most part an option I wish I could take more often -- I simply don't have the energy most days to deal with it, after everything else. My budget for fun stuff would be higher if I did.But, for now, it's about $100/mo plus whatever people want to give me. You mentioned oscilloscopes and signal generators. I have an oscilloscope, but it's a Tektronix 422 from the era in between semiconductors and ICs -- it's all discrete parts inside, but there's like three tubes. It's also built like a WWII battleship and weighs enough to be used as one's anchor. I happened to have a love affair -- briefly ish -- with PICAXE microcontrollers, and I met a fellow who lives a couple states away, a retiree who spent the 70s at Borroughs Computer designing machines the size and shape of executive desks... this was his old work scope. (Thx again Ray!) He even sent me the original manual with it. If I had a signal generator and maybe a few other bits and bobs I could work my way through the manual tutorials and maybe then I'd get some use out of it, but as it stands I've no idea, TBH, how to do anything but stand next to it looking real stupid because RN I don't know how to use it. I managed to get a recommendation from Blondihacks herself regarding logic probes... for the curious, she uses an Elenco model off Amazon, apparently. I have the same model nowit gets used once in a while. I've plenty of multimeters as well -- but they only tell you so much about a circuit in flux. Oh, and I have one of those multi-component testers off eBay. The kind with the 9v battery and the yellow PCB and the ZIF DIP socket. You put your whatever part in the socket and push the button, the screen comes on and it thinks to itself for a few minutes and then Magic 8-Balls out what it hopes you wanted to know.But if it isn't cheap, it's a donation or a birthday/Christmas present. I have an old TL866A programmer -- I can't afford to upgrade it -- it's one of the eBay ones, for better or worse. I paid... $65ish for it for my birthday five or six years ago. Later that year (IIRC) a local pal of mine who is somewhat less messed up (very much not a people person, but he at least can do well enough to run his own place) gave me -- sans the useful stuff he could strip, i.e. drives and RAM -- a castoff HP Mini 5102 with a few dents and a BIOS password that literally nobody on Earth still remembered. Pulled the chip and introduced ti to my programmer... no more passwordI still own that machine and it still works. I wish batteries were cheaper for it (it's an unpopular model so they're stupid expensive) -- the one it has leaks like a sieve, but replacements are worth more than I can justify.Gimme a sec and I'll explain why I need that inductor. This is already something like a short novella's worth of text (sorry) so I'll do that as another post.

author: starhawk
author_rank: Regular Contributor
timestamp: June 05, 2021, 06:52:38 am
content: So one of the places I hang out now and again is Hackaday. They've actually got a couple different contests going on RN... best that I not give my opinion of The Hackaday Prizelet's just say I'm a tad outspoken in regards to it.But they've this thing they're calling the "Reinvented Retro" contest, where you take old junk and do pretty things with it or the like. I *desperately* want to win this -- the top prize is a $200 shopping spree at Digikey, on their dime. I'm more of a Mouser kinda guy, personally, but I'm not about to be choosy if someone else is payingSee, all those standard components that most folks can just reach for, whether it's chips that have numbers starting in 74LS or every resistor or capacitor that doesn't command a triple-take at the value... the stuff nearly everyone "just has on hand"... I don't have that on hand. I simply don't have the money for a standard parts base and I desperately want one. Guess what that $200 will go for if I can get it?I have an idea involving a couple computer bits and a late-90s Magnavox CRT-based color portable TV that my stepmother's late father left behind a couple decades ago. Alas, composite video being what it is, even at 800x600 resolution, text on that screen for eg icons and menu bars is... well if you squint hard enough to give yourself a migraine you can sort of make it out, is my experience. So I'm trying to find a way to sharpen the image. I'm using a scan converter that takes a VGA input, the kind from eBay that has the buttons on the side and comes in a silver plastic housing, and turns it into Composite. Suffice to say that my computer system of choice here has no expansion other than four USB2.0 ports, and its CPU/chipset is remarkably anemic and non-upgradeable anyways. I'm fine with these limitations -- but sticking eg an old PCI graphics card with a composite jack on it, on the back end of this thing is a physical impossibility AFAIK. (I'm pretty sure nobody makes USB-to-32bit-PCI bridge hardware... if such a thing exists in cheap-on-eBay form, I want to know! I've searched high and low, I don't think it existsFWIW, the PCIe Mini Card / PCIe x1 to PCIe x16 adapters that use a USB3 cable are not using USB3, just the wires of the cable.) So I have the external converter.I found this mention online --https://circuit-diagramz.com/inexpensive-video-enhancer-circuit-diagram/-- and while it's a questionable one at best, given the URL, it occurred to me that since I have an apartment full of electronics junk that borders on being a genuine certifiable eWaste collection (lol), a dig through one box or bag or another ought to yield something that I could glom across the signal and ground pins of the composite-out jack on that scan converter that would satisfy the requirements of the design at that site, and that if it didn't work, taking it off would be exactly as trivial as putting it on... i.e., a 30sec job with the ol' Hakko 926 (bought secondhand on eBay and looks like it served in a war... and no, it's not the one with the fancy ESD plastics) that's otherwise barely worth mentioning. A quick dig found me exactly that... the motherboard of an HP Compaq tc4400 my mother had for several years and used for almost certainly less than four dozen hours probably ever. I've already hacked a few parts off for other projectsand it was an absolute NIGHTMARE of a machine to deal with when it was operational anyways -- GOD I hated that thing -- so I'm all too happy to pull more from itMy concern with the markings were primarily the idea that maybe the '631' or 'BTC' meant something of significance to the part's values and performance -- eg a max voltage/current rating or the like... in the latter case, something like how the J/K/L/whatever on some caps has a meaning to it (sorry I forget *what* meaning -- it's late here and I'm getting sleepy). I'm glad that they're largely irrelevant.I'll try that inductor trick in the morning unless it's genuinely not worth it -- and if others want to suggest better alternatives, I'm happy to try them as I can -- and I'm also happy to tell what I have (and don't) on hand to cobble them together. Just... they WILL be cobbled-together bodge jobsit's just what I do.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 05, 2021, 07:57:57 am
content: Tek 422, ah, a fine vintage. A bit slow, but still enough to do basic switching supplies, logic circuits, even a little radio (though it'll be a bit of a mystery if it's oscillating in the 100s of MHz or something!). I grew up on a 475 myself, spoiled for bandwidth in comparison...Alas, the "video enhancer" won't do much -- it has the effect of increasing the high-frequency gain of the composite signal. To understand the effect, you need to know about NTSC encoding.The signal is basically baseband intensity, i.e. between 0 ... 1V (or whatever it is, actually like 0.3 ... 1V? I forget exactly) is simply black to white, and periodically there's a dip to 0V (or negative?) for horizontal sync. The sync pulses themselves change width during a few lines, becoming wider, which triggers vertical sync.But that's only black and white. What they did for color, is add a radio band on top of the signal. The intensity (luminance) is the lower (baseband) 0 to 1.some MHz -- which means the effective pixel clock is double that, and dividing that by horizontal sweep (15.7kHz) shows why the horizontal resolution is so pitiful -- and the rest is color information. There's a colorburst tone inserted in the signal periodically, which is separated out and used to sync up the color demodulator. The color information is amplitude and phase modulated, around a center of 3.58MHz -- meaning, in the same way that the sine and cosine functions are complementary (mathematically,orthogonal), we can decompose the waveform centered around 3.58MHz as sine and cosine -- independent components summed together. And these are used to map out the color space, converting the value of those components to sums and differences of R, G and B (I forget which exactly). The effect is, if you take the angle of those components (that is, atan(y/x)) you get hue, and magnitude (sqrt(x^2 + y^2)), saturation. So you get the HSL (hue-sat-lum) space, this is where it comes from -- invented way back in the 1950s.And we can calculate what effect that RL network probably has. 75 ohms and 10uH has a cutoff frequency of Fc = (75) / (2 pi (10u)) = 1.19MHz. Which is coincidentally right where luminance falls off (so, it will be sharpened just a little bit), and where color takes over (so colors will be WAY stronger).And this has the effect of boosting the magnitude of the colors, and the magnitude corresponds to saturation, so the colors will simply be oversaturated.In short -- you're limited by the frequencies used by NTSC modulation itself, and you can have some effect on the picture, certainly, but nothing that increases the resolution. TVs already go to some lengths to do the best with the crappy signal they get; if your set proclaims "comb filter" somewhere on it, it's probably doing just that. (A comb filter produces the sharpest divisions between luma and chroma bands, giving the sharpest pixels with the least bleeding of color and intensity.)You may not be SOL though -- simply altogether better modulations do exist. S-video supplies luma and chroma on separate signals, more than doubling the bandwidth I think it is. SCART works similarly I think. Component (completely independent R, G and B) does even better; this is basically what a VGA monitor does, and everything after that with the exception that DVI (digital) and HDMI do it via digital signaling, but it's still basically raw R, G and B being blasted out.If your TV doesn't have these connections available, it's possible that you can hack into the circuit to find their onboard equivalents, and patch in new signals -- this may be dangerous of course, there are high voltages inside the TV. You'll want to understand the circuit first (find a service manual or schematics if you can?).That gets you up to the resolution set by scan lines and video bandwidth. Which are... harder to change. (I've always slightly wanted to, like, convert an old tube TV to something like 800x600 SVGA, with whatever is necessary -- I think it's still possible using tubes, but it would be a lot easier with transistors of course. It's not going to be a small project, it would involve redesigning a lot of circuitry.)Tim

author: Ian.M
author_rank: Super Contributor
timestamp: June 05, 2021, 09:30:20 am
content: *If* your TV is an international model that supports PAL, and your scan converter also supports PAL, you *may* be able to convince the scan converter and your graphics card to work in 720 × 576, 50Hz interlaced mode, which is the native resolution for PAL region DVDs. That will immediately give you 20% more vertical resolution than NTSC. As the color subcarrier for PAL is approx 24% higher than that for NTSC, *IF* the TV switches chroma/luma filters for PAL mode, you'll get corresponding improved horizontal resolution.To do so, you'll *probably* need a utility for your graphics chipset that allows you to set custom resolutions.Are you stuck with this setup as your only VGA monitor? If so, it may be worth trying to scrounge a 1024x768 SVGA monitor. Most people *think* they need widescreen so 4:3 flatscreen monitors are reasonably affordable in thrift shops (if you find one that sells electricals). Unfortunately you are about a decade too late to easily find SVGA CRT monitors.

author: starhawk
author_rank: Regular Contributor
timestamp: June 05, 2021, 10:27:36 am
content: It's quite stupidly late here and I'm about to go to bed. I'm glad I got distracted and never pulled up that inductor! (LOL)The TV identifies itself, in various ways via a sticker on the rear. As best I can tell it is a --MagnavoxModel RD0510 (Arr Dee Zero Five One Zero)Suffix "C"Sub-Model C103 (Cee One Zero Three)Serial # 70926475Manufactured sometime in October 1997 in Malaysia.The sticker with Model and Serial #s mentions a "USA Limited Warranty Registration" with the final word appearing on its own line. That text is centered, and the model info includes the "sub-model" (which, to be clear, is *my* term -- the only case where I've done so). The Suffix marking is in the upper-right corner; Manufacturer name-logo in the upper-left, and Date of Manufacture (one presumes; it is a date, flanked with "Prod. Date" on two lines at left and "MSE" on one line at right) a bit right of top-center.Listed with the Underwriters' Labs (UL Listed lol) under # 843T as a "Television Receiver" and filed under "UL File No. 69278".Molded into the plastic on the underside of the unit, in with the usual "don't stick your tongue in it for a taste while it's on" type irresponsible-bonehead-lawsuit-prevention warning label material is the usual FCC Part 15 compliance line that we're all familiar with, but also -- intriguingly to me -- a mention of a "DHHS Rules 21 CFR Chapter 1, Subchapter J" with which it also complies.Alas, I've never really been able to find anything useful by way of schematics or component datasheets. I'll take photos and get chip/etc labels off it tomorrow tho.[ Off-topic discussion tangent (maybe interesting but *definitely* otherwise irrelevant) ]Being the child of a former attorney (my mother, who had to retire early because of unexpected health reasons and is now highly disabled herself as a direct result), I find that an interesting mention -- I've never seen it before -- as well as an interesting *form* of mention -- normally the citation format would be "21 C.F.R. § 1.326-1.368" -- generally you don't go by Chapter/Subchapter, but by 'section', which is basically paragraph-groups, organized by structural relevancy, within Chapters, Subchapters, etc... for example, the famous "501(c)(3)" for non-governmental organizations which can claim federal tax exemption in the US by being non-commercial entities prohibited from collecting net profits, is in full, "26 U.S.C. § 501(c)(3)"... Title 26 of the United States Code (the formal body of federal statutory law -- CFR is Code of Federal Regulations, which is different), Section 501, Paragraph "C", Subparagraph "3". § is the symbol used for "section", BTW. As an aside... of course, lawyers have the phrase "any attorney who represents him- or herself has a fool for a client" for a reasonso consult your local friendly licensed attorney first! but it's worth noting that 26 USC 501(c)(3) (whoo, lazy variation) specifically prohibits such organizations from effectively any political activity. I'll simply note that there are some notable sorts of organizations which arguably somewhat flirt with that line there in a fashion somewhat predictable to anyone who lives in the USA.[ OK done ]

author: starhawk
author_rank: Regular Contributor
timestamp: June 05, 2021, 10:36:46 am
content: @ Ian.M -- it's for a contest; see post starting with "So one of the places [...]" only a bit of the way up, thereit, er, fits the theme.I've plenty of old Dell LCDs in XGA (1024x768) and similarly limited (or so it would seem nowadays) non-widescreen resolution over in the closet, almost all of which take only a single VGA input. But they don't fit the themenor does any other LCD, really. I've also got a Radio Shack Port-A-Vision that is outwardly similar except for a battery compartment for a rather criminal number of "D" cells and the fact that it's black and white and a bit shorter in depth, and -- in another closet -- a mid-1990s 15ish inch (IIRC?) CRT TV that's nothing but cheap plastic the whole way through (IIRC it's a GE-by-Chinese-license job, ugh! /shudder ) and a Samsung CVL-422 fixed-resolution 640x480 / 256 color job from 1992 that was part of my first computer -- which I also have the rest of, except I've misplaced the keyboard. (I think I may have accidentally shed it, sadly, in fact...)So, tl;dr -- I have plenty of better displays, but I'm using this particular one for a very good reasonEDIT: yes, I know I said I was going away for the night (early morning at this point, sadly) but then I got a pal contacting me on Discord who is nearly impossible to get ahold of most of the time and I wanted to chat with him. So we're chatting.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:04:16 pm
content: Sorry I'm late (please don't ask).MAN that TV was a pain in the backend to get apart. IDK who designed this thing or where, exactly, but I have words for their cost-reduction dept. Lots of words. Most of them are four letters.BUTAfter a LOT of jiggering around and a LOT of swearing (including in some languages I'm not entirely sure actually exist) I have photos. Pixdump incoming shortly, I need to get them over to my laptop from my phone. Please stand by.I also need to get myself some lunchfor those wanting a head start to things, here are the chips I can find...On the underside of the analog board, there's an "LC7534 5H5"; the three-character part is on its own line. No other markings, even to indicate manufacturer. Looks like it gets hot, it's got that 'white dust effect' that chip plastic gets when it gets heated repeatedly.Also on the underside of the analog board, an "AN5707NS" by Matsushita (oh the jokes I want to make) -- has the old 'M'-in-a-box logo where the M looks like it's sitting cross-legged a little bit. Second line reads "718A163E" and the third line is the logo at left and the country of manufacture -- Japan, predictably -- at right.Finally, *also* on the underside of the analog board, there's a chip marked "358C" and "722" on the second line. Very obviously an LM358... what is that, quad op-amp? I'm too lazy to Google it right away.No other PCBs have chips on the underside. The neck board has transistors on it, but no chips, and the switch-board for the front only has switches and wires, no actual componentry (!) so I kind of wonder why they wasted such a large PCB on that. I guess that's why I don't work for MagnavoxTwo chips on the big primary driver board on the bottom of the thing (the analog board is upright, at right from the front of the TV, the neck board is... a bit left of center at the very back when mounted properly, and the switch PCB is at front, upright and immediately right of the CRT from the front)... one is marked "AN5512" with another boxy-sitting-'M' Matsushita logo, a big dot, and then "771" on the second line. There is a thick vertical bar or line across the two lines of text at far left, before any of the rest of the text. /shrugThe other chip, likely the star of our show since it's a 54pin Slim-Pitch DIP (they were kind enough to mark the pin #s at the corners on the silkscreen!) -- UGH how I hate non-2.54mm/0.1in-pitch DIPs! -- is marked "TOSHIBA" on the first line, with an extra-large second line (just in case we really *needed* the large-text edition, I suppose, lol!) identifying it as a "TA8680BN", and a third line reading "M'SIA 733UA111". Apparently this chip was made in Malaysia but they wanted to save a bit on inkThe flyback is also a Matsushita (the joke I want to make, BTW, involves replacing the last five characters of that name with a six-character adjective invoking the property of "being and/or possessing the qualities of fecal matter" in distinctly vulgar form which will otherwise get me bannedso I won't use the word itself... if you know, you know... if you don't, wait till you're older and you do!) and is marked "H.V. DANGEROUS" in red on the first line -- no duh! (...or, if you're old enough, no, er, vulgar fecal matter) -- "4992-054" on the second line. The third line is an extra-large 'M'-sitting-in-a-box logo and then "78" a wide space and "3". There is a fourth line where it proudly proclaims, widely spaced across the *entire* label (which is really a bit wider than otherwise necessary) -- "MADE IN JAPAN"! Nice, I guess.Now I'm gonna go get lunch while my photos mosey on over to my computer from my phone. I'll be back shortly

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:49:53 pm
content: PIXDUMP!!Apologies for my being Absolutely Not A Photographer... and for the fact that, even after processing to minimize filesize (my phone takes STUPIDLY huge photos) I'm still gonna be spreading this across several posts.So this one has the 'first look' photos -- warning labels (LOL), service diagram, and what it looks like before I swear-worded it apart.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:53:33 pm
content: The whole PCB pie open on my workbench (a light table, as I'm -- amongst several other things -- an artist as well)... and JUST that because the forum's attachment size thing quite understandably gets miffed when I add on the next part. The switch PCB puts it to 5.3 megs! So that will have to go on its own post.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:54:18 pm
content: Switch PCB. Yaaaaaaawn.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:55:17 pm
content: Neck board.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 06:56:45 pm
content: ...an'na analog board

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 07:01:17 pm
content: Details, details! A spot on the neck board that got obscured by cabling earlier, and one on the analog board in similar form. None of these cables are removable BTW. In fact, the ground leads from the analog and switch boards tie to a contact against the side of the CRT and then to its little hold-in-surround-bracket-thing... I had to clip that wire, it's soldered on!Somehow I only did the BACK of the main / CRT driver board (!!) and a detail shot of it, so I've got to go fix that. Hang on, lol... thaaat's next.EDIT: lol I'm an idiot!

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 07:13:48 pm
content: OK... main board time. This is going to have to split across THREE posts. Sorry. First post (this one) will be the overall board itself. Second post will have detail photos... third will be a single remaining detail photo and the back of the board. After that I'm going to log off for a bit -- this laptop has been running with only suspend/sleep-state at night (I run Linux Mint BTW and it's DEFINITELY not hibernating) and it also has a minor overheating issue, so I'm gonna shut it off and let it cool down for a bit because it desperately needs it right now.

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 07:14:50 pm
content: Details part one. LOL @ that one tiny diode in the corner!

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 07:25:40 pm
content: Last for now. That one remaining detail photo, plus the PCB back. I'll see if I can find any PDF datasheets once I'm back up.BTW, this laptop is a Dell XPS 15Z. I have a local friend who runs a tech shop. This is a Dell XPS 15Z he couldn't sell, so he gave it to me. It's admittedly largely wasted on me, I don't game hardly at all (and when I do they're either literally MYST series games or clones thereof that really run best in XP or Win7... or stuff that just genuinely *requires* DOSBox or a nostalgia machine outright, lol)... and I've not traced out its issues properly; given their nature, I'm pretty sure that the one issue that isn't (a) the LCD is delaminating because Dell brilliantly glued the lid shut and I've not got the money nor the inclination to replace it, so the upper-left corner of the screen is a bit blotchy and (b) I really should go in and deal with the thermal glop that's obviously expired -- a bit prematurely; I had forgotten that the heat intake was on the bottom and did something stupid in that regard or (c) Dell didn't quite know how to write reliable USB3 drivers for Windows and somewhere after Win7, Microsoft forgot how to code, so Windows 10 needed a reinstall reliably every ~6mo because Cortana code underlies not just everything search stuff in Win10 but the entire taskbar and Start Menu everything, and the slightest bit of filesystem corruption (which is not hard to get to) kills it hard... both of which were solved with a Linux Mint install...the last remaining issue, anyhow, is an odd one and it only happens on battery. I'm pretty sure it's a component-level mainboard issue and I've not got the inclination to try and ferret it out, so it remains extant. Anyhow, I need to shut down for a few to let it cool down... I'll be back in a bit

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 06, 2021, 08:49:35 pm
content: Looks like this one does most of the work,https://pdf1.alldatasheet.com/datasheet-pdf/view/115189/TOSHIBA/TA8680N.htmlplus support circuitry, it seems to take in video IF (usually ~40MHz?), which is going to be from the RF front end (free-standing metal box?), and demodulates all the signals needed to drive the CRT, including YUV (goes to the video amps) and sync (goes to H and V deflection amps). It's no slouch either, it's got OSD (on screen display) so probably a tiny hard-coded MCU and video generator of its own.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 10:44:15 pm
content: Nice!Now if only I could read Sulu Fencing Challenge(sorry) -- anyone got a PDF translator app or should I use Google?EDIT SOMETIME LATER: Google Translate can't read it right, the encoding is weird. Anyone speak bad anime or should I wait for the dub release? LOL(sorry again)

author: starhawk
author_rank: Regular Contributor
timestamp: June 06, 2021, 10:54:23 pm
content: FWIW... the AN5707NS is a tuner chip and the AN5512 runs vertical deflection on the CRT. I have both datasheets. They are attached, as is the one for the TA8680N.

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 12:18:31 am
content: Quote from: Word Salad!This is what I get out of online translation tools. "Ohhh myyyyy!"I give up. (Also, sorry... yet again... I have a tremendously awful sense of humor. Blame my father.)

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 02:13:11 am
content: Seriously.Translation help requested with regard to that one TA8680N PDF. It's in Japanese and I don't read or speak a word of Japanese and Google Translate doesn't do it right.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 07, 2021, 03:40:21 am
content: Would be curious for a better translation, but there's also not too much more that a couple cover sheets will say about the device. Details are hidden in whatever the full version of the datasheet is, which may well be OEM license eyes only, who knows. (My assessment is based on the block diagram, which is a little less inscrutable.)Matsushita by the way, is the electronics manufacturing side of Panasonic. Old and very large company, one of several famously large conglomerates in Japan.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 03:52:39 am
content: Well if you can at least tell me which pins are inputs and what they expect to have put into them, I'll be a happy fella.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 07, 2021, 05:01:22 am
content: Inputs, hard to say. Looks like pins 40, 43 are composite input, 43 after the detector (the crystal filter being a 4.5MHz LPF I suspect) and 40 for external input (which you already have access to I think?).Not sure what the network is between pins 31 to 38.Possibly the H sweep can be varied with pins 24 and 25, but I wouldn't be surprised if the device has an internal range limit, so it's not like you're going to hack it to 800x600, or even 480p for that matter (which needs more than double the H sweep frequency already).YUV output appears to be pins 15-18, this would be the place to try cutting traces and injecting component (RGB) or some combination thereof. These traces may go to another circuit (which would be signal conditioning), or straight to the transistors on the CRT neck board.You can follow traces and components on the PCB to see if this is correct.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 06:20:32 am
content: From staring at the diagram, here's my read.SHR probably means "shrink" or some variant thereof. No idea about "ADD". "HV Sepa" *could* refer to High Voltage... buuut Occam's razor cuts that one out to more likely be Horizontal/Vertical Separation and someone forgot the '/' character. (Forgive me listening to Ole Man Willy of Ockham here, but the other dude of his era, give or take, with a straight-razor in the hand and a gleam in the eye was a barber named Todd, and his gal pal next door made a living as a pie-baker... with the customers of his who didn't want to pay up!) That goes to something "H AFC" -- no points for 'H' = "Horizontal" again; Google says 'AFC' is "Automatic Frequency Control" and I'm not gonna argue. "BRT BLK" probably has something to do with brightness and blankingand that feeds into... a whole heck of a lot of other stuff.It strikes me that most of the circuitry in this chip kinda has to be analog just by its nature, and therefore pins 31 - 38 probably form a control network for whatever control carp (sounds fishy!) handle that sort of important, basic stuff. Pins 24 and 25 are actually caught up in that mess, didja notice?they appear to more-or-less control (via the 31-38 Network and the "32 fh VCO" voltage-controlled oscillator -- hey, an acronym I *don't* have to Google! NiceLOL) the horizontal centering, and -- via a different box labeled "Sync [integral italic-f symbol]" -- the vertical centering -- "H C/D" "V C/D" -- Horizontal and Vertical Center DeflectionI really can't make heads or tails, hardly, of the input on Pin 43, but Pin 40 does indeed look promising in regards to Composite Input. I don't remember offhand what YUV is and there's that extra pin that probably goes from the "DEMO" box right above, which appears to output some sort of coloration signal. I'm going to go edumacate myself (lol) on YUV and I'll be back shortly.

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 06:47:36 am
content: Huh. So YUV is basically S-Video -- split luma/chroma -- but *more* split, so that the luma is split in two.I guess that makes it SS-Video? Don't tell Chevy Nova owners!Alas, my VGA-to-Composite scan thingymadooberajiggamabob (I swear that's a technical term!) only has four-wire composite... luma chroma and two grounds. Pathetic! But I remembered I had this thing a pal of mine, that tech shop guy who gave me the laptop, he gave me this thing as well. He gives me a lot of thingsmost of them are still looking for uses a few years on, and this thing is one of them. It's a "CGA/EGA/YUV TO VGA" converter adapter board whosimadoober (another technical termI promise) which is marked elsewhere as a "GBS 8200 V4.0" with a (presumably manufacture) date of "2014.02.17" under that. It's Greek to me! (Odd, the rest of it's in Chinese...) but maybe it's also useful? I see a set of what appear to be binding posts of all things (not the screw-em-down-or-banana-plug-in-the-middle kind, these are literally like blunt nails on a plastic carrier, five of them) crammed in one corner with a VGA connector, an eight-pin large-ish JST (?) connector that's about 0.1in / 2.54mm pitch (nice!) and that spills over to a set of three RCA jacks in colors of green blue then red, with four buttons in the far corner for whatever OSD setting system it has. The RCA jacks are also labeled Y (Green) Pb (Blue) Pr (Red) if that's any help.The eight-pin JST (?) connector is given the pinout GND-GND-VS-HS-S-B-G-R BTW. Going back and continuing up the right side, counter-clockwise, there's an otherwise unlabeled jumper "P8", two pins, and a four-pin probably-programming header -- VCC-TX-RX-GND -- plus a footprint for another similar one -- GND-VCC-SDA-SCL. Up at top-right there's a barrel jack and just before that a two-pin JST (?) header like the sort you'd see on a cheap LiPo flatpack battery from eBay (I hear they make great campfire starters, just short across the pins!no that was a joke don't do that, yikes) and over at top-left there's another VGA port and a JST (?) connector that's twelve pins and looks to be 2mm pitch (aww) -- it's marked R-[?]-G-[?]-B-[?]-H-V-[?]-[?]-[?]-[?] where [?] denotes an unmarked pin.There are also three trimpots in the lower-left corner with all those connectors.IDK if that board is at all useful -- but maybe? I'd love to FINALLY have a use for it!

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 08:18:55 am
content: OK... Pins 15 16 17 18 of the TA8680N trace out on the TV as follows...Pin 15 winds its way lazily along quite a long scenic route to R336 -- 330R 5% -- which goes to Pin6 on the wider of the two black ribbon cables on the neck board. That feeds through D455 to 0vGND -- sorry, I can't ID the diode, but it drops a full volt so it's something *vaguely* similar to a 1N400x series, probably -- as well as to Q451 -- 2SC1473A marked "C1473A R.62" with an overline on the '2' and the '1' on the first line almost impossible to see -- it's an NPN "triple diffusion planar" transistor using BJT nomenclature. Pin 3 is the Base and that's the pin being driven by our signal. Q451 Emitter goes to C451 -- 470pF ceramic disc -- then R454 (560R 5%) and a jumper (!) to R453 (2k2 5%) to VR453 (5k? trimpot -- code 502 -- it's the R Cut Off). Q451 Collector goes to R451 (1k5 5%) parallel with R452 (2k7 5%). R451 leads to C454 (1nF ceramic disc, code 102K) across Pins 1 and 2 of the narrow ribbon cable (!) which is a three-pin job. R452 goes to Pin7 of the CRT socket, marked "R" on silkscreen.Pin 1 of that 3pin cable goes in a number of interesting places. C554 (black Marcon, 16v/1000uF "CE-SE") to what seems to be marked "+B10.5" on the flyback but isn't really entirely legible. Not following that further. A jumper connects to a trace with C673 and C674 in parallel (C673 = 47nF/code"473J" | C674 = 56nF/code"563J") which feeds a VERY large solder joint under the flyback, in parallel with another, smaller one, which appears to be marked "ABL" and two others that are a bit larger, sort of middling in size. D673 is in parallel with the two caps; it appears to have an instant of conduction and then ~0.2v but is otherwise impossible to ID, sorry. I'm not following that trace further, either.C672 (black Marcon, 160v/4.7uF "CE-SE") joins Pins 1 and 2 of the cable (!!!) which then joins via jumper lead and R553 (56R 5%)... with the line from "+B10.5" on the flyback. OK, I guess I'm following that further, after all, whether or not I want to! That feeds a 5pin inductor, T551. Not tracing further. The trace that hosts R553 also feeds back to L604 which is part of power conditioning. It's marked "330K H78" and is *immediately* behind the power-input barrel jack.Sheesh. Pin 16 is next.

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 10:43:02 am
content: OK... finally lol... Pin 16......very quickly goes to C318 (black Marcon, 50v/2.2uF "CE-SE") then through R332 (100R 5%) and then D302 (unmarked glass bead, red inside with a yellow stripe on one end), and *then* R335 (1k 5%), and finally a wire link... to 0vGND right where it comes in. R332's end also branches, however, to a surprisingly long jumper, then a trace that wends its long, long way to Q304 (2SD1740 "Triple Diffused Planar" "High Power Darlington"; marked "D1740 S.RV" with an overline on the 'V'. It's a power transistor of some sort...) The datasheet prescribes ONE package for it, and the package used in the TV is a different package. Judging by the silkscreen, tho, it's Pin 3 that the lead goes to, which is the Emitter. Not tracing Collector on Pin 2. Pin 1 is Base, however, which couples to 0vGND via C313 (2.7nF ceramic disc, code 272K) but also leads to R502 (1k 5%) via a jumper. R502 leads to R504 (15k 5%) which leads to a complex network -- not following -- but also to Pin 9 (VCC) of the AN5512 via a jumper. Not following from there.That wasn't too bad!

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 11:12:33 am
content: Right, so Pin 17.Pin 17 follows Pin 15's path in parallel form, down to R337 (330R 5%, just like R336). It goes to the neck board via that 6pin wide ribbon cable; it's Pin 5 on that cable. On the neck board, this is tied via D454 (identical to D455 from before) to 0vGND and then to Pin 1 of Q452 (another 2SC1473). Pin 3 is Base. which has an RC network across it (C452 -- 470pF ceramic disc, code 471 -- and R458 -- 560R 5%) which leads to R460 (150R 5%) tying it to Pin2 on the wide ribbon cable.Meanwhile, the transistor side of the RC network also goes on a long winding journey to R462 (3k3 5%) which cuts to Pin 3 of the wide cable; it also branches nearby to R459 (2k2 5%) leading to the wiper contact of VR455, the Green Cut Off trimpot, marked "502" as per the others. Notably the three trimpots (R G B Cut Offs all) of relevance here, are all "502" trimpots, and all have a common leg -- facing the tiny orange Philips-head adjustment knob it's the rightmost leg. This leads to Pin 3 of the wide cable.Well that wasn't so bad!

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 11:47:49 am
content: So Pin 15 winds up driving the R electrode gun of the CRT, demonstrably. Pin 17 essentially inevitably drives the G electrode gun, although I didn't trace it quite that far. By implication, Pin 18 nearly unavoidably drives the B gun, although notably I've not traced it yet.The termination of Pin 16's signal near the AN5512, and what almost inescapably is its analog control network, strongly implies that it has something to do with a sync signal of one sort or another.BTW, the two ribbon cables are labeled by way of signal --For the 6pin -- from Pin 1 to Pin 6 -- +B Y 0vGND B G RFor the 3pin -- from Pin 1 on -- 0vGND +B H+B is going to be a grid bias of some sort I suspect (?), and the H kind of stymies me where Y is VERY clearly the other character. Presumably these are nonetheless Horizontal and Vertical Sync drive signals. 0vGND is obvious. B G R should be the color signals.One wonders if I could not create a simple lock-latch scheme using 74xx or CD4xxx parts, using 74xx14 Schmitt Trigger Inverters to turn the HSync and VSync signals to the CRT to digital levels suitable for driving a set of analog latches that would grab-and-hold the R G B levels put out from my VGA port at that instant to feed to the CRT. In fact... I kind of wonder if the 'latch' could be built using a CD4053 with the NC/NO side leads hooked to the VGA input and the switch-COM (as a figure of speech, I know it's not actually like that) hooked to a tiny capacitor as a form of simple, jerry-rigged DRAM, with a single 74xx14 inverter toggling between states, with the other cap shunted to 0vGND. The idea is that the VGA output would charge the capacitor to whatever voltage it was at just before the latch swaps, so that it dumps to the CRT just before dying out.Thoughts on that one?

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 01:02:08 pm
content: Quote from: starhawk on June 07, 2021, 11:47:49 amYeah it probably sounds a bit odd and a bit janky -- but I can make that stuff work pretty well usually. [EDIT after this coz I hit "Post" too soon, LOL] Odd and janky is my kinda thing. I thrive on that stuff, yo!

author: starhawk
author_rank: Regular Contributor
timestamp: June 07, 2021, 10:54:51 pm
content: Feedback plz?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 07, 2021, 11:28:17 pm
content: No need for flip-flops or switches, it is what it is. And if it isn't, well, it ain't gonna work.Do you have a component (NTSC) source? Easiest hack is probably to set up a standard composite input, but bypass the YUV output from the decoder and inject RGB directly there. Signal levels may not match, but at least to see if it works at all it should just be a dim picture if anything, I would guess.VGA isn't going to work, at least not at any meaningful resolution: the TV is made for the lines it is (which is 222/223 lines per field, alternating). The nearest traditional mode is likely 320x200 60Hz, which I think has same or similar timings, or if nothing else there may be enough range in VHOLD, HHOLD to be able to track it. I'm not sure about patching in raw sync signals; I wouldn't recommend cutting drive to the outputs themselves as the TV needs those always running to generate voltages (that's where the ~100V for video drive comes from).This is full of high voltages, particularly around the flyback transformer and CRT. Be very careful. Probably a good idea is to solder wires onto components near the decoder chip, and lead them out the enclosure where they're secured in a breadboard or something. Probe with a multimeter first, see what voltage is present. Then you can see about patching signals into that board.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 08, 2021, 01:08:47 am
content: Component, no. Is there a simple way to derive it *from* VGA?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 08, 2021, 02:26:56 am
content: Not sure how you'd generate sync inputs for the chip from it.If it's synchronized with the composite output, you might be able to use both?Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 08, 2021, 03:04:33 am
content: Would one of these do it, acting otherwise as a VGA passthrough? I have one that looks *identical* to this board, per photo from Google Image Search.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 08, 2021, 08:06:13 am
content: Kinda doubt it... that looks to be a scan converter, the input and output timings are completely different.Maybe it has a mode, or some source, that would be compatible; I'd have to see a detailed manual, or get out an oscilloscope.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 08, 2021, 08:54:31 am
content: Well unless the OTHER one puts out Composite Sync and VGA-out at the same time, and I don't think it does...:-/

author: starhawk
author_rank: Regular Contributor
timestamp: June 09, 2021, 06:40:58 am
content: Quote from: starhawk on June 08, 2021, 08:54:31 am...?

author: starhawk
author_rank: Regular Contributor
timestamp: June 10, 2021, 03:52:21 am
content: This is the VGA-to-Composite converter (image attached), the *exact* one, identical style/manual/accessories/etc.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 10, 2021, 07:54:19 am
content: Afraid I'm not familiar with it.Tim

author: starhawk
author_rank: Regular Contributor
timestamp: June 12, 2021, 07:21:22 pm
content: Sorry I was absent for a bit. IRL stuffs.I'm still thinking about this. TBH I'd far rather do signal conditioning on the input end of things, if I can, than to try and bypass the TV's electronics. I know that there's only so much one can do with a composite signal, but I'll try what I can. Any suggestions?EDIT HOURS LATER: would something like the reference schematic in the attached PDF help? I can get one of those chips for like $10 on eBay, NOS so it will actually work. (I've bought from that seller before, as well, they're trustworthy.) I'll have to pick up the coils on eBay too, but it's kinda hard to screw up an inductor lol. The rest is a set of caps that I definitely have on hand. But: will it improve anything?