[HN Gopher] New motherboard improves old CRT television
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New motherboard improves old CRT television
Author : rbanffy
Score : 169 points
Date : 2023-08-18 11:19 UTC (1 days ago)
(HTM) web link (hackaday.com)
(TXT) w3m dump (hackaday.com)
| MaxikCZ wrote:
| 2 pictures and a video somehow left me wanting for "before" and
| "after" pic showing how the television was improved
| djmips wrote:
| It's not that improved in picture quality, it's mainly improved
| in features - like the ability to display NTSC X PAL signals
| rwmj wrote:
| This article is blog spam - you probably want to watch Adrian's
| video directly: https://www.youtube.com/watch?v=MoqflFfvkR0
| userbinator wrote:
| The fact that it's for a CRT is the surprising part, but
| "universal" replacement boards for LCD TVs have been available
| for a while too. Here's a rare review of one, on a site that has
| sadly disappeared within only a few years:
|
| http://web.archive.org/web/20190511065920/http://redlightgre...
| qingcharles wrote:
| Wow. Who knew such things existed? Fantastic. I'd hate to
| resolder that data cable from the LCD though.
|
| That board was cheap as hell, had every input and decodes MP4
| video. WTF.
| chris37879 wrote:
| I bought one to repurpose an old laptop screen, if the screen
| uses a releasable connector, you can probably find a board
| that connects to it
| userbinator wrote:
| I guess that one reviewer either didn't bother to order one
| with the right connector, or received it with the wrong one,
| but the pinouts are usually very standardised so there's no
| need to resolder the LVDS cable.
|
| There's lots of videos on YouTube about these boards;
| unfortunately the vast majority seem to be in Indian or some
| other Asian country's language (despite English titles and
| descriptions). Here's one of the few English ones I could
| find: https://www.youtube.com/watch?v=C2YTL25iyHU
|
| Another (unvoiced, English text descriptions) :
| https://www.youtube.com/watch?v=kM8_kJENdoQ
| RajT88 wrote:
| China is paradoxically filled with brilliant engineers making
| genius products, and mediocre engineers making products whose
| listings appear to be genius.
|
| I fucking love gambling on AliExpress.
| jacquesm wrote:
| That's a great observation. I've bought stuff there that I
| could not even believe was as cheap as it was, I thought
| the price must be a typo and for sure it'll be adjusted.
| For electronics the pricing tends to be lower than the BOM
| at maximum volume discount when sourced from a large
| Western supplier.
|
| And the vast majority of it just works, though I've had one
| or two duds.
|
| But you need to be sharp when it comes to things that plug
| into a wall socket, open them up to inspect that they are
| safe.
| chpatrick wrote:
| I think electronics are just super cheap to make and
| they're overpriced when sold abroad.
| distract8901 wrote:
| Electronics are crazy. Depending on the amount of skill
| and/or effort you have available, there is an enormous
| spread of possible implementations at different price
| points.
|
| For instance, I develop a product that we sell for $2500.
| When the company brought me in, the raw cost of the
| electronics was about $250. Right now I've got it down to
| $50, and I expect it to fall to $20 or $30 once we start
| producing at scale.
| permo-w wrote:
| I think we can describe that as just being filled with lots
| of engineers
| RajT88 wrote:
| Fair.
| ComputerGuru wrote:
| Thanks for sharing that link - it's quite a thorough write up!
| I wish there were things of like quality for CarPlay retrofits.
| CamperBob2 wrote:
| _I wish there were things of like quality for CarPlay
| retrofits._
|
| Porsche Classic is all I can think of (
| https://www.caranddriver.com/news/a42571042/porsche-
| touchscr... ). Hopefully other manufacturers will get on
| board with that idea at some point.
| ComputerGuru wrote:
| Oh there are a ton of interposer boards you can buy shipped
| direct from China that add CarPlay to an existing oem head
| unit the same way you can get reverse camera support (high
| jacking the video output when a certain but is pressed or
| the gear shift changes). It's just that they all have
| massive quirks. I've seen the Porsche Classic CarPlay
| retrofit and it's absolutely the best, but these third
| party solutions are available for most makes and models but
| all have to a of quirks and idiosyncrasies that are never
| presented up front.
| zczc wrote:
| Looks like machine translation from Russian original:
| https://mysku.club/blog/aliexpress/67872.html
| userbinator wrote:
| Thanks for finding the original, and I did suspect it was
| translated from Russian due to the odd phrasing, but if it
| weren't for that site translating a copy and Google
| subsequently finding it, such interesting things might've
| never gotten discovered. As I mentioned in the other comment
| here, there's lots of videos on YouTube about these boards
| too, but barely any in English.
| squarefoot wrote:
| Here are some more links on those controllers and various LCD
| data:
|
| https://www.mattmillman.com/info/lcd/rovatools/#comment-8933...
|
| https://sites.google.com/site/lcd4hobby/home
|
| https://github.com/ghent360/RTD-2660-Programmer/
|
| http://openrtd2662.ru/
|
| https://www.codeforge.com/article/258602
|
| https://hackaday.io/project/179868-all-about-laptop-display-...
|
| https://www.panelook.com/index.php
|
| https://lcdtech.info/en/
|
| https://repairalltv.com/main-board-universal-ds-d3663lua-a8-...
| notRobot wrote:
| Thank you. You're downvoted, but I always really appreciate
| link dumps like these as a kick-off point for my own
| research.
|
| Edit: here's one of my own!
| https://news.ycombinator.com/item?id=33359963
| 29athrowaway wrote:
| Have lots care when opening a CRT TV. In fact, don't do it unless
| you know what you are doing.
| timonoko wrote:
| If you wear rubber gloves and keep your other hand in the your
| pocket, I dont see any actual problems.
|
| Also long sleeves are good, I was recently zapped at the wrist
| when fixing an oscilloscope.
|
| I think maybe the 20 kV abates rather quickly on its own,
| because I dont remember using much any caution when unplugging
| the anode plug.
| wkat4242 wrote:
| Has to be serious rubber gloves to withstand 20kV :) the
| simple doctor's ones won't do
| Am4TIfIsER0ppos wrote:
| Surgical latex gloves are not what I picture when someone
| says "rubber gloves" but something more substantial
| typically used when cleaning in a shape that borders on a
| rubber gauntlet.
| wkat4242 wrote:
| I know but not everyone who reads this would be as
| experienced to know this :)
|
| Some people would still think "it's rubber so it doesn't
| conduct electricity so I'm fine messing with this TV".
|
| But yeah CRTs are now so rare that I agree that it's very
| very unlikely for someone without much knowledge to
| tinker with them. You have to be really an enthusiast to
| even still own one let alone try to repair one instead of
| picking up a nice cheap flatpanel.
|
| Personally I'd forgo the gloves (real protective ones are
| so clumsy it's hard to really do something productive
| with them) and make sure the caps are fully discharged.
| Though generally I'd steer clear from this stuff as I
| know I don't understand it well enough. I came up in
| electronics during the final years of CRTs so as my
| knowledge grew they became deprecated and I never really
| got the full grasp of them.
| bregma wrote:
| When I took a TV servicing class in high school in the 1970s we
| were told just to keep our left hands in our back pockets so
| the discharge will ground through our right side and not across
| our hearts. The biggest hazard was breaking our hand on the
| chassis as we jerked back from the shock.
|
| I never heard of any kids getting hurt, so it was fine.
| paul_funyun wrote:
| The risk of death or serious injury messing with CRT displays
| is grossly overstated (note the lack of data on related
| fatalities). Use common sense and you'll be fine.
| allenu wrote:
| I remember fixing up a CRT on an arcade machine I had in my
| office at work at one point. I read up on how to discharge it
| and made a makeshift tool to do the job (i.e. an insulated
| screwdriver with a wire attached to ground). I was pretty
| scared and even made sure to do it during work hours when
| others would be around in case I got zapped unconscious. :)
| Once I got was able to do it a couple of times, it really was
| no big deal, but I did take care not to get too close to the
| back of it while the thing was on and exposed.
| sixothree wrote:
| Worse, it's never been made clear to me which parts are the
| dangerous one. Just a lot of vague hand waving. Which I guess
| is fine if you don't want liability?
| formerly_proven wrote:
| That's probably because most people posting this useful
| advice don't know themselves.
| somat wrote:
| If unsure or nervous around electricity, just ground the
| segment you are working on first.
|
| But the parts that should make you extra cautious have
| wires with a lot of insulation so they look thick. those
| are the 20Kv bits. you also will want to take the time to
| drain any big capacitors. you can just short the leads or
| if you are feeling conscientious(and don't like sparks)
| drain them with a resister(100kohms or so) between the
| leads.
| rwmj wrote:
| The cathode ray tube is a giant capacitor. During operation
| it is charged to 20+ kilovolts, and it takes a long time to
| discharge even after being unplugged from the wall. (Some
| but by no means all TVs have a circuit which discharges the
| tube). There are also large capacitors in the power supply
| which maintain hundreds of volts even after being
| unplugged. When the TV is connected to power, the flyback
| transformer (a large circular device soldered to the main
| board) generates a range of voltages from hundreds up to
| 20+ kV which are wired to various parts of the tube. Some
| of these are present on the neck board which is exposed at
| the pointy end of the tube.
|
| US TVs are extra spicy because they sometimes have no
| earth, so if the power is wired backwards (either in the
| plug or more insidiously from the wall), everything metal
| inside the set can be live.
|
| If you overvolt the tube (a worry with this replacement
| board actually) then it can emit x-rays. Most "modern" CRT
| main boards have a circuit which detects this, but maybe
| older ones or cheap knock-offs don't.
|
| In short, if you don't know what you're doing, stay away.
| Hydraulix989 wrote:
| If you're not sure about it, best to stay away. With a
| cursory web search or YouTube search, you can find plenty
| of information.
| rwmj wrote:
| This is a case where having the right tool is actually a good
| idea. It'll have plenty of insulation and usually a VU meter
| showing the voltage (so you can see if it was charged and
| watch it drain). A screwdriver doesn't really have enough
| separation between you and the 20+ kV :-/
| uncletaco wrote:
| In what cases of repair is having the right tools _not_ a
| good idea?
| 7speter wrote:
| Its not a matter of not having the right tool is not a
| good idea, but sometimes, because of cost and or
| circumstances, you have to improvise and/or make due with
| what you have.
| willis936 wrote:
| A few sets I've had need to be on and open to make
| adjustments. I'm never a fan of that.
| wiz21c wrote:
| Not entirely related but I didn't find much information about the
| NTSC/PAL decoding schemes. Lots of introductory material but
| nothing about what they actually did in televisions back then
| (especially the filtering side). I guess it's because of
| patents...
| Animats wrote:
| It's covered in detail in Wikipedia.[1]
|
| Here's the NTSC color standard in the Federal Register.[2]
|
| The data sheet for a modern NTSC/PAL decoder IC.[3]
|
| Details of early color TV receivers.[4]
|
| [1] https://en.wikipedia.org/wiki/NTSC
|
| [2]
| https://www.govinfo.gov/content/pkg/CFR-2018-title47-vol4/pd...
|
| [3] https://www.analog.com/media/en/technical-
| documentation/data...
|
| [4] http://earlytelevision.org/color.html#systems
| wiz21c wrote:
| I was thinking about 2D filtering. But your comment triggered
| a new DuckDuckGo search and it happened to have some bits of
| information :-)
|
| https://www.extron.com/article/ntscdb4
| MegaDeKay wrote:
| Mike's Amateur Arcade Monitor Repair on YouTube reviewed a
| similar 25" Universal Arcade Monitor Chassis a couple years back
| and was "blown away" by it. Definitely worth the money. High
| praise from a guy that knows CRTs inside out.
|
| https://www.youtube.com/watch?v=i3u9sWDeoYE
| caymanjim wrote:
| The built-in game is Sokoban[1]. I know it from Nethack, but the
| one in the TV is just like the original.
|
| [1]: https://en.wikipedia.org/wiki/Sokoban
| CTDOCodebases wrote:
| It's worth noting that there have been community efforts to
| develop an open source design CRT chassis:
|
| https://vimeo.com/591387422
|
| https://github.com/tdaede/td-crt
| gattilorenz wrote:
| oh, that's great. Anyone selling kits of this? Or an Aliexpress
| version less geared towards TV and more towards gaming
| monitors, with VGA, composite and other useful input for retro
| computers?
| CTDOCodebases wrote:
| Not that I know of.
|
| RGB hacking is a thing though so for 15khz (~240 x 60hz) aka
| 240p it is often just simpler to tap into the OSD display
| chip (lookup jungle chip mod) input an RGB signal.
|
| https://www.youtube.com/watch?v=VKhEpyFfAHs <- basic RGB mod.
|
| https://www.youtube.com/watch?v=ANSxASanZes <- advanced RGB
| mod.
| gattilorenz wrote:
| Been there, it works, but if the original crt board has
| issues (and you're not good at diagnosing them) it would be
| great to get a good quality replacement
| CTDOCodebases wrote:
| Good point.
|
| What I would like to see is a board made for larger
| 100/120hz TVs. They often get no love from gamers due to
| the lag/processing of 240p content so they get junked. It
| would be a good solution to the lack of multimode CRTs.
| They are so rare/expensive.
| SomeoneFromCA wrote:
| Oh yeah, Adrians Digital Basement..Highly recommended youtube
| channel.
| nickt wrote:
| This video and reading the recent article referencing Brimar
| valves (of the vacuum tube variety) [1] led me down the rabbit
| hole of, how hard can it be to make a few CRTs. Despite growing
| up with them, it turns out I had no idea. Lots of ovens and nasty
| chemicals involved - see for yourself in this great old video
| [2]. I wonder if anyone in the retro scene is eccentric and rich
| enough to give it a go...
|
| [1] https://brimaruk.com/
|
| [2] https://youtu.be/32yYfTVIzBE
| TedDoesntTalk wrote:
| > https://youtu.be/32yYfTVIzBE
|
| Great video. I've got to 6:06 so far no mention of nasty
| chemicals yet.
| skissane wrote:
| Transcript: https://youtubetranscript.com/?v=32yYfTVIzBE
|
| From the transcript (I dislike watching videos), it appears
| the video never discusses the chemicals involved - but I'm
| sure some of them are rather toxic. It is an old film, and
| when it was produced people didn't see the toxicity of
| chemicals used in manufacturing processes as being as worthy
| as note as people do today - both environmental and workplace
| health/safety issues were less on people's radar. Plus it
| obviously is marketing/PR for the manufacturer, and who wants
| to mention toxic chemicals in something like that?
| hetman wrote:
| It's worth mentioning though that in general as our
| technology has gotten more exotic, so too the chemicals
| needed to manufacture it have gotten more toxic.
| snthd wrote:
| Is there some underlying rule/"law" of fabricated
| products shrinking in scale requiring increasing energy
| density/control for their manufacture (more reactive
| chemistries) presumably to counter a general backdrop of
| entropy / entropy-density?
| Aeolun wrote:
| 10:37 has hydrochloric acid
| mrob wrote:
| Sounds like hydrofluoric acid to me, which is even more
| dangerous. But seeing as you're making a vacuum chamber
| anyway, perhaps oxygen plasma could be substituted.
|
| https://en.wikipedia.org/wiki/Plasma_cleaning
| CTDOCodebases wrote:
| I remember hearing the main issue is that the glass is made up
| of a significant amount of led so even if it was commercially
| feasible it would be legally impossible to sell, import or
| manufacture new CRT tubes due to the regulations many developed
| nations have in place.
| mrob wrote:
| Lead glass is only used for the back and sides of the tube.
| It can't be used for the faceplate because x-rays make it
| turn brown. Instead, barium-strontium glass is used for the
| faceplate. It seems that use of lead is only a cost
| optimization, and the whole thing could use barium-strontium
| glass instead.
|
| Searching for "lead glass CRT browning" on Google found this
| sample chapter from an unidentified book, provided by the The
| Society of Photo-Optical Instrumentation Engineers, which
| includes some details:
|
| https://spie.org/samples/TT54.pdf
| NL807 wrote:
| The chapter is from:
|
| Kenneth Compton, "Image Performance in CRT Displays", SPIE
| Tutorial Texts in Optical Engineering Vol. TT54
| wkat4242 wrote:
| It's kinda mad we used to stare at an X-Ray gun though :)
| especially the ones in the 80s didn't quite filter all of
| them out.
| [deleted]
| willis936 wrote:
| How are car batteries sold, imported, or manufactured?
| CTDOCodebases wrote:
| That was the explanation I was given when asked.
|
| I imagine different regulations apply to different
| products. Also obviously different countries have different
| regulations.
|
| Lead makes up 20-25% of the contents of the glass of a CRT
| tube so I imagine that restrictions like those listed in
| the link below would cause issues.
|
| https://dtsc.ca.gov/restrictions-on-the-use-of-certain-
| hazar...
| elzbardico wrote:
| There are exemption. And if you think of it, it is a lot
| easier to properly dispose and recycle the plates in a car
| battery than in electronics solder or glass.
| jdietrich wrote:
| I can't speak for any other regulations, but the EU's RoHS
| has a specific exemption for lead in the glass of cathode ray
| tubes.
|
| CRTs are still being actively manufactured, primarily for
| avionics and military applications.
|
| https://eur-lex.europa.eu/legal-
| content/EN/TXT/?uri=CELEX%3A...
|
| https://www.thomaselectronics.com/manufacturers/
|
| https://moores-glass.co.uk/products/cathode-ray-tubes/
| Aeolun wrote:
| It may just be me, but this video actually seems detailed
| enough to replicate the process if you have the right
| materials/machinery.
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