Tearing apart a huge rear projection tv to explain the parts and how it works. 0:00 History 0:44 Exterior 1:32 Teardown 6:57 Circuit Boards 10:12 Chip Identification 11:37 High Voltage Circuitry 12:50 CRT Assembly 16:29 Ethylene Glycol
I repaired so, so many of the projo tv's...I was in the TV Repair bizz for almost 40 years...some were built very well and produced excellent pictures, but, once lcd hit the market, projection tvs were rendered useless. DLP was actually an excellent form of projection TV, but they weren't practical to continue that technology. It was actually amazing the amount of technology that went into tvs from the 80s to early 2000s... Many manufacturers were operating at break-even costs during those years. The TV Repair business was very profitable during that time, but, it all came to an end by 2014. Now it's strictly retro and antique restoration....some services are still needed, but the service business is a part time hobby today.
Thanks for commenting. I’ve always been more fascinated by DLP. After taking one apart I’m not surprised that they are just breaking even. CRT rptvs are interesting too, but more primitive. It seems like they would be prone to more convergence issues.
The fresnel lens magnifies the projection that's hitting the mirror in the back and makes it fill the screen area, but that alone makes the image look warped, exactly as it would under ba magnify glass. The lenticular sheet (straight lines) straightens the image, eliminating that warping. The acrylic sheet protects everything else and make the physical structure of the lenses invisible to the viewer, unless their face is right against the screen. This same technique can be used to make your own rear projection screen, though if you're not bouncing off a mirror and instead pointing straight at the rear of the 'lens stack' you'd need to add a light diffusion layer like LCDs have. I'm not an expert, i just spent a lot of (fun) times messing around with stuff like this.
You know what's odd, when I was younger, I would always be fascinated by these big TVs, one time while I was bored, I looked into the TVs front still covered with the material, and found Red Green and Blue lights, at the time I was confused on what those were... Eventually the TV was trashed... I never got to see the inside of it. It was an old RCA tv. I think it was from 2000 or 2001.
When I was a kid theses TVs were already 10 years obsolete, but people still were getting rid of them. My parents wouldn’t let me take one home, so if it was in my neighborhood I would take parts off before the garbage picked it up. I think it’s surprising to most people that most of the tv is just empty space. Only the bottom part has the parts.
Breaking open CRTs is potentially hazardous. There isn’t much on the inside either, it’s mostly just an empty vacuum. The front glass has a phosphor powder and the electron gun is inside the neck (skinny part) of the tube. Regular full color CRTs have a metal structure inside called a shadow mask.
I just took apart a similar tv design but did not break it down like your did. I wanted the fresnel and CRT lenses but had no clear idea what the other stuff was. I’m glad I kept the electronic assembly so I can try examine and maybe use some parts later. Thank you!
These are great for light gun games. You can get huge tvs like this up to 70 inches and have all the benefits of a crt since they use tubes to create the image. Only set back is the brightness.
Greek letter mew for 'micro'-processor. Old service guys used to get sun burn or something from the x-rays emitted by those CRTs. It's good that you show data sheets
Some chip manufacturers make it difficult to find data sheets. Fortunately, Sony is not one of those brands. I always enjoy looking at the data sheets because they are full of useful information.
@@BGTech1 A lot more is learnt from fixing things, studying how they operate with an oscilloscope and reading datasheets, than from any college or university course.
Rear projection TV's are fun to tear apart, but for those looking to tear apart these sets, be careful of the oil that's used inside of the display assembly as it may cause irritation/burning to the skin depending on what kind of oil is used within.
Excellent video! I am thinking about parting out my 13 year old Toshiba tn55x81 cinema series hd rear projection TV (which still works, but has not been plugged in for months) to harvest it's front lense and whatever else cool there is to salvage (optical lenses, heat sinks, speakers, casters, etc.) Besides warnings about ethylene glycol within the lense housing, the RU-vid videos warn about "discharging" the CRTs and capacitors to avoid a nasty shock. Any advice about this project?
As long as your tv has been sitting for a few days you have nothing to worry about. The charges dissipate as time goes on after you last turned in on. To discharge the crts and flyback, connect a flathead screwdriver to a piece of wire and the other end to the metal chassis. While only Holding onto the plastic screwdriver handle, slide it under the anode caps for each crt and make contact to the metal piece in the center. After that it’s safe to disconnect.
That's the problem with those Is you always had to sit directly in front of them The fresnel lens and then go Is designed to spread the light out The piece with the vertical lines handles the vertical and horizontal where are you reading the material from is it the manual
In Czech Republic these are quite rare to see. I was looking for one for a long time until I was going through a scrap yard and found one! All the color guns are working but there is something fucked up in the video circuitry. I'm planning on using the color guns for some kind of project. Maybe a some sort of spot light. It's actually quite amazing how TVs got simple over the years. Anyways, nice video!
@@BGTech1 Here brand new CRT TVs are being sold purely because of people who cannot afford an LCD TV. However, rear projection TVs are incredibl rare not only in Czech Republic, but also Germany, Poland Slovakia etc. The one that I found was a one-in-a-milion coincidences, it eas imported from the US, hence why it was so rare.
@@Sonic_The_Electronic_Madlad Interesting! Rear projection TVs were the more expensive alternative to crt TVs so they always have been less common that crts. It’s probably been at least 15 years since crt TVs have been sold in stores, Now days you can buy a full HD LCD tv for very cheap. Around 8-10 years ago people were throwing crt TVs out very often. I was 9 or 10 at the time, and I would pull parts from them right on the curb. Back then people didn’t care.
I have a Sony LCD projection TV model number KF 350 w e610 I am trying to get a picture and I just get static in it. I can play my DVDs on it when I switch it to the channels I just get static
Hello, i recently disassembled a rear crt projection tv similar to this one, i kept the lenses from the projectors, the frensel lenses and the mirror inside. I was wondering if any of those parts could be toxic or irradiated. It might be a dumb question but those crts produce radiation from x-rays right? If that's so wouldn't that make the other parts slightly radioactive? Is it safe to keep the mirror as a simple wall mirror? Also any advice as to do with the lenses? They seem only good as magnifying glass i tought about making a telescope but they dont seem good enough for that. Thanks for he help
Hi, There is no need to worry about radiation. While CRTs do give off some X-ray radiation when in operation, the radiation isn’t nearly powerful enough to irradiate other nearby objects or people. It is perfectly safe to keep or repurpose parts from the tv. I haven’t found a good use for the tree lens assembly mounted to the CRTs, but they do act a lot like a standard magnifying glass. I believe each assembly has two or possibly more different lens inside which might be interesting for experiments.
i was curious what was the purpose of ethylene glycol in those lenses. surprisingly i could not find a good answer on the internet. so for fun i decided to ask chatgpt and it said it's used as a coolant to transfer heat away from the tube. i guess it makes sense, but it's still not clear to me why it needs to be a liquid. apparently it sometimes becomes contaminated by a fungus.
That’s correct, it is also used because it creates a quality optical coupling between the crts and lens assembly that mitigates luminosity and picture quality losses. crt fungus is a bit of a misnomer, as it has nothing to do with a biological fungus. In some conditions the ethylene glycol will form small crystals suspended in the fluid that will block light and decrease picture quality.
It does make sense that if you want to cool the light emitting surface of the CRT carrying away the heat with a liquid makes sense. How else would you do it without blocking the picture?
Well, these are not exactly light bulbs, rather they are miniature tv tubes. The lenses that come on them already focus the light somewhat so I’m not sure what you mean by “spotlight”. You could probably have one of these aimed at a wall in a dark room and be able to see the video playing.
Hola una pregunta yo tengo una de esas se ve muy bien apenas limpie los proyectores y se ve muy clarito pero se ven los colores un poko separados como puedo arreglar
As long as your tv has been sitting for a few days you have nothing to worry about. The charges dissipate as time goes on after you last turned in on. To discharge the crts and flyback, connect a flathead screwdriver to a piece of wire and the other end to the metal chassis. While only Holding onto the plastic screwdriver handle, slide it under the anode caps for each crt and make contact to the metal piece in the center. After that it’s safe to disconnect.
The exterior should be fine to touch, even if your ground is not connected well. (I’m assuming you mean the ground connection on the power cord, not something internally)
@@thestickchannel1845 I’m not sure it could be because of a short somewhere. I’ve seen those explanation things swollen too, I guess it just happens over time as it ages.
@@chrisbailey7384 I thought so too, but the phosphors are actually red, green and blue for each of the tubes. My guess is that the red and green isn’t the exact shade required for accuracy reproducing the whole spectrum of colors, and the filters correct the shades. I’m not sure why this isn’t an issue with direct view CRTs though.
@@BGTech1 OK, fair enough if it was faulty :-) . Where possible, I think these rare TVs, or even just their parts, should be preserved as you can often use TVs, or their tubes in old rear- projection arcade machines and they do look great for old games (when tuned-up). Giant 4:3, native 15kHz with no lag and big scanlines is a nice thing.
Red, green, and blue are the primary colors of light, as opposed to pigments, which use the RYB color model. Since TVs work by emitting light, they use the RGB color model.
Red, Yellow and Blue are for mixing paint. The blue paint in the primary color is more azure/light blue towards cyan shade which allows mixing yellow and blue to make green wheras the blue light in the RGB is a very deep royal blue almost indigo shade of blue.
