Questions tagged [tv]
Use this tag for technical aspects of TV (video formats, for example). Shopping questions are off-topic and repair questions might be too localized.
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ON TV Decoder Magazine Article/Circuit?
Starting in the 1970s, there was a scrambled TV service transmitted over the air called "ON TV" in our region. I think "Radio Electronics" magazine published an article about ...
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2
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Salvaging/splitting up some backlight LED strips to make a lightbox
I'm trying to reuse some old HD425Y1U51-T0L6 LED Backlight LED strips to make a light box.
They look like this:
The closest link I found for them (but no spec sheet) is https://www.shopjimmy.com/...
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How were high voltage vacuum triodes used in TVs?
How were the grids of TV high voltage (over 10 kilovolt) vacuum triodes operated back in the day?
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TV motherboard / LDVS and universal LED panel
On eBay you can find hundreds of Samsung (but also LG, Philips, etc.) Smart TV motherboards (see e.g. here https://www.ebay.com/itm/132373029756).
What I would like is to have more of those ...
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Can a CRT last 100,000 hours or even 300,000?
Online, I could find that high-quality cathode-ray-tube displays (whether be it for a computer monitor or a television set) have a design lifespan of 30,000-50,000 hours of cumulative operation. I ...
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How to reuse analog TV - small Sony in particular [closed]
SOLVED SOLVED
SOLVED SOLVED
Min of 30 characters required
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HDMI CEC connections and ground reference
I'm trying to work with the HDMI-CEC bus and a STM32 microcontroller (currently on a Nucleo-144 board).
I'm connecting a cut HDMI cable with some Dupont wires soldered on it, to interface to the ...
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Why do CRT TVs need a HSYNC pulse in signal?
Could someone, please, explain how old CRT TVs reacted to input signal, specifically to VSYNC and HSYNC pulses?
Do these pulses control the electron beam? For instance, if signal would consist only of ...
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Television repair - connectors and standards for display panel and controller boards
All my experience comes from 2 flat TVs, so my knowledge is quite reduced and questions have to be quite broad.
Questions:
Are there standards or common practices from manufactures about connections ...
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Raspberry pi inside CRT TV - piggyback off a 220v line on a TV main board?
I would like to mount a Raspberry Pi device inside an old CRT TV (yes, I am well aware of CRT safety protocols, I've been restoring them for a few years now).
The Raspberry Pi is powered using 5 volts ...
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IR frequency counter
I want to deign a frequency counter in this way:
A specific frequency (33 kHz) is radiated by an infrared transmitter from a distance of 10 m to the infrared receiver for 100 ms.
After amplifying the ...
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Could I use an RF modulator to broadcast signals from a Raspberry Pi to an analog tv over the air without the use of a coaxial cable?
"Long" story, but I connected a digital-to-analog converter (for OTA TV) to my mom's 1984 Samsung CRT, and now I'm wondering, could I broadcast (on low power, of course) HDMI outputs to a TV ...
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TV tuner pinout
I was looking for some old VHF/UHF TV tuners for an RF receiver experiment and stumbled upon this old tuner from a shop. It has a label showing TELE1-030A and an IC inside shows ALP008M (Terrestrial ...
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TV backlight LED strip doesn't work, but individual LEDs work fine
There are 9 LEDs (3 V each) connected in series in the LED strip. I tested individual LED with 3 V applied across, and it works fine, but when 9 × 3 V is applied across the whole strip, the LEDs are ...
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What is a circuit I could use to generate valid analog TV signal?
What is the simplest valid analog TV signal and what circuit is required to generate it?
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How were the phosphors applied to the inside glass tube of older colour CRTs?
I've been reading into how CRTs were assembled and how they work, but I can't seem to find any concise information behind how the coloured phosphors inside the inner glass tube were applied. There is ...
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73
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TV Hisense HLE4815RT not tuning cable signal
I have a Hisense TV HLE4815RT (mainboard: RSAG7.820.5649), that suddenly stopped tuning cable signal, it just says "No signal". I tried different cables, removing some splitter, ...
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DVB reception: Why do I need to add a coaxial cable to my installation to improve SNR of the signal?
I have the following installation:
Dipole antenna <------> Coaxial cable (3 m) <-----> DVB receiver
If I connect my dipole antenna directly to the DVB receiver, removing the coaxial cable (...
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Can coaxial TV aerial cables be flat/ribbon? To go under thick rug for TV opposite aerial socket
A round shaped one would cause a ridge in the carpet.
I already have setup a flat ethernet cable under the rug for similar scenario whereby device is opposite ethernet socket.
Update it's to carry DVB-...
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My speaker connected to my TV is making weird noises only when playing videos [closed]
Apologies if this is the incorrect forum, if anyone knows of a better forum to ask on I would appreciate the redirection.
I have a very specific issue regarding audio playback from my TV. I have a ...
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Reduce audio signal from TV when volume exceeds a certain level
I hate how loud action scenes are in movies, compared to how low the talking parts are.
My TV is currently connecting to some speakers with a jackstick.
Is it possible to measure the volume with ...
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How to switch off the CATV signal on a splitter port
I'm trying to create some automation of switching off the CATV signal on a splitter port.
Using a regular 5V Arduino relay module I've tried to interrupt the wire from the center of the coaxial cable ...
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Defective Transformer Replacement
I've been working on repairing a TV psu, and discovered that the transformer in it is faulty (reading O.L. on every combination of pins except for diagonal in ohms mode on the DMM)
I've been looking ...
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Fixing composite video distortion caused by brightness changes
I'm modifying an old CRT to take NTSC composite input (it only accepts RF over coax.)
I have got a good signal going in but it has this weird distortion going on.
When the image is dark the pixels may ...
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294
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How to convert composite AV signal or RGB to luma (grayscale)?
As the title says- how can you convert composite signal into luma?? As we all know, composite is just what it says, composite video with grayscale and color signal combined and luma is just grayscale. ...
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What is 'mis-registration' and 'mis-collimation' of television signals?
I was reading about early televisions and television cameras, and I came across these terms with no explanation....
They appear on Google on a few pages, but again I cannot find a definition....
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what do the colours of the wires on stereo speakers signify from old TVs and laptops? [closed]
I have a few laptop and a TV stereo speakers salvaged from old electronics in my possession and I have noticed a pattern that I cannot understand. Both the left and right of these speakers have two ...
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Why does changing CRT to HDTV lose antenna channels? [closed]
We have an internal antenna that is connected to a tiny CRT TV through a digital converter box. I recently replaced this CRT TV with an HDTV, and I removed the digital converter box since the HDTV ...
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Replacing a 6 V LED backlight with two 3 V LED backlights
I have a 65" TCL TV which have backlight problem and I have another 60" TCL TV with broken screen. Now when I opened both TV to swap with LED backlighting strips, and I and I noticed the 60&...
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Why my television provider doesn't measure the coaxial cable length?
I recently put cable TV in my room (we already had cable TV before, but not in my room). The technician from my TV provider, through a split, ran a coaxial cable up to the TV in my room. When he did ...
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Meaning of TV Backlight LED strip details
I am learning electronics and I just disassembled a broken TV with the purpose of reconverting it into a smart light lamp.
The issue is that I don't understand the details of the backlight LED strips. ...
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2
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331
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troubles getting serial port tv to work
i recently posted a question, but didn't had an answer (my fault :) ).
my question wasn't straight-forward and clear.
so my final goal is to communicate between nodered (raspberry-pi) and my lg tv. I'...
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How to get static on CRT screen instead of black screen?
The TV in question is a Sony Trinitron KV-14M1D CRT. I know it sounds backwards but I need the screen to show white noise for a project (oscillograph); but there seems to be a static block that ...
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Why don't LG RS232 commands work when the TV is on (only responds when off)?
I'm writing a new question after stumbling across this question which appeared to have similar symptoms:
LG RS232 Commands partially working.
As the other question noted, the power on command ...
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Old tvs, how did storing settings work, and what changed in the tv when we tuned a channel?
I don't have an EE background, but I would like to understand some aspects of old TVs.
When we tuned channel what exactly changed inside the tv. Was there a circuit card in the tv where something ...
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How did old television screens with a light grey phosphor create the darker contrast parts of the display?
Many old television screens have a very prominent "light grey" color to the glass, I'm guessing from the phosphor, create darker areas if the effect of electrons make the phosphor glow?
Is ...
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How to test TV LED backlight failure [duplicate]
I recently picked up a Braum (Aldi) TV from the nature strip to play around with.
The TV seems to work perfectly fine (Channels, DVD input, sound etc) except that there's no working backlight.
I've ...
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"shark teeth"-like PCB feature in high voltage section of modern HDTV
I found this tooth-like non-masked, solder-covered trace pattern on modern single board HDTV.
It's in the 120VAC "HOT" section of the switch-mode PS.
Looks like some sort of spark gap or ...
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465
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How to adjust picture geometry of a CRT TV?
I have a HD CRT TV (Silva Schneider 26 inch) which failed recently. So I took apart a working CRT TV (Philips L01-2E AA, 20 inch) and took its mainboard and connected it properly to the HD CRT tube.
...
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Which components should be checked on a faulty tv power supply? [closed]
So, I'm new to working with electronics and I didn't study electrical engineering or anything related.
I've collected some dead tvs and monitors over time hoping that I'm gonna fix them.
I managed to ...
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Very old dual coaxial TV outlet, how to fix it to connect to a modern TV? [closed]
i've recently moved into an older updated apartment building and want to connect to the TV outlet but have a connection that i've never seen before. Can someone point me in the right direction of how ...
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Light coming from the room influencing TV
Inside the TV Remote we have a LED of infrared light which sends commands to the TV.
Isn't it influenced by the light of the room(if any?).I thought if an electron in the valence band absorbs a photon ...
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Why faulty, old CRT TV produce ozone
I have an old CRT TV which had to be switched ON for half an hour or so for the picture to stop being blurry and be 'viewable'. During this initial warm-up time there was a 'static' like noise coming ...
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LED indicators intensity standards
I am trying to find any resources on the LED parameters (i.e. preferred intensity and luminosity ranges) that are used as indicators in various home appliances, such as Networked devices (i.e. routers)...
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How to ground a flyback transformer?
I designed a 50,000 volt power supply, that I am having problems with on grounding the HV side of the output. The HV appears to be injecting HV into my logic sections through the ground, damaging the ...
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649
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Ratio of colors to produce white in color television
If you consult pretty much any book on the theory of color television, it says that because the human eye is more sensitive to green than red or blue, the reference white for color television has been ...
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GSM vs TV broadcating
Is it true that GSM signal's field strength in the atmosphere is dependent on the current number of users whereas for TV and FM broadcating the field strength is usually constant, independent of the ...
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Why are color difference signals transmitted rather than R,G,B signals?
In color television systems back in the early days, people used to transmit color difference signals (Y-R) and (Y-B) along with Y, which is the luminance signal. My question is why are color ...
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How do I reinforce a cardboard antenna for outside use?
I bought Mohu Releaf cardboard antenna. It works much better outside than inside. Mohu explicitly advises against outdoor use of its indoor models, yet I wrapped it in a plastic bag and hung it out of ...
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Will an RF modulator provide NTSC System M spec video from a DVD player?
I've been attempting to recreate the effect of an old NTSC television broadcast lately with the use of DVDs. The DVD-Video spec allows for up to 720 x 480 pixels at a display rate of 29.97 frames per ...
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