Using S-Video & RCA on TV

The tv I currently use has a bad coaxial input jack and makes the picture very snowy. Therefore I use either the s-video or rca jacks and have no quality issues.

I have a digital cable box with only rca or coaxial (no s-video) So I have the rca connected to the tv. My dvd player is hooked up via s-video. I cannot leave the s-video plugged in to the tv if I want to watch cable. I have to unplug the s-video and it is a pain because it is a heavy tv to move and the s-video jack is hard to plug in unless you actually pull the tv out and can see what you are doing.

Is my assumtion correct that my problem is that I only have 1 video input on this tv (I think I’ve seen tv’s that have 2 channels for video input)? In case it isn’t clear I’m talking about the video selection you can make on the remote that actually displays the word “video” on the screen. If so, is there any hardware I can purchase, like a switch box perhaps that will accomodate me so I don’t have to keep unplugging the s-video? Or perhaps even other solutions.


I’d be stunned if Radio Shack didn’t have the part you describe.

Also, fixing the coax input is fairly easy.

But getting a box that accepts different inputs should be as simple as visiting Radio Shack.

Your TV probably automatically detects the presence of an S-video and that overrides the RCA video input. the only way around this I can see is to eschew the S-video altogether and use an RCA audio/video switch box to select the desired input. Radio Shack has a two-input selector switch, and there are others with anywhere from two to four inputs, any of which should serve the puropse. I’d get one with four inputs, just for purposes of future exapnsion.

Bless you! :smiley:

If I’m not mistaken, Radio Shack has a switchbox that will take multiple inputs, either RCA or S-Video, and give RCA or S-Video out, so that you can mix & match your inputs. That way you could plug both devices into a single switch and take the S-Video output.

Yeah, but the electronics in it are pretty crappy, and you completely lose any benefit of using S-video in the first place. At $35, it’s not worth it, IMO. The two-input switch is about $10.

Also, fixing the coax input is fairly easy.QUOTE]

Can you possibly expand on that? I’m not a complete elctronic idiot, but opening tv’s can be somewhat dangerous. However, I’m willing to try it if you think it’s just a matter of opening it and disconnecting the part and reconnecting a new one.

Radio Shack, here I come.

Thanks, QED, sounds like exactly what I need. Any other electronic gurus concur with QED about the picture quality difference between the 2 suggestions so far? For what it’s worth, I don’t notice any quality difference between s-video and rca. Perhaps a more trained eye does, but mine do not.

You don’t need to open up your TV. Get the switch from Radio Shack and connect the RCA cables (from your cable box and DVD) to the inputs on the switch. Then run another RCA cable from the output of the switch to the video input on your TV. If you are also using your TV for sound, instead of running it through an external amp, you’ll need to run your audio RCA cables to and from the switch also.

Yes, there is a difference in quality between RCA and S-Video, but unless you have a really good monitor and know what to look for, you may not notice the difference.

Here is the kind of switch you’re looking for.

Thanks, Fat Bald Guy, but that was actually directed at Philster who suggested repairing the coaxial input shouldn’t be that hard. I’ve heard different in the past but I’m willing to learn.

It’s more of an issue with video games, in a way. The stationary images (status bars, life meters, etc) in video games tend to get what is termed “pixel crawl” (temporal aliasing) when using the composite video input (RCA jack), but not when using the S-Video.

It depends on exactly why the picture is snowy. If the problem is in the tuner circuitry, you can’t fix it unless you’ve got some solid background in electronics. However, if the problem is merely a cracked or cold solder joint where the wiring inside the TV connects to the F-56 coax jack (which is a fairly common problem), then resoldering is easy enough to do. You don’t even need to get close to the dangerous stuff inside, if you’re careful.

Replacing the coax input means swapping out the board it is connected to. On most TVs, it is quite expensive and not worth it. On a high end TV, you could order the board and drop it in, possibly requiring some solder.

I would guess by the limited number of inputs on your TV, you don’t have a high end unit that would justify spending 200+ U.S. dollars on.

Opening a TV is dangerous with the unit plugged in, but can anyone explain how it might be dangerous with the power off?

Some of the capacitors in a TV can hold a (possibly lethal) charge for hours, or even days, after power has been disconnected.

Thanks, Joe Random, glad I asked.

I think that resolves the issue about attempting repair.

In all fairness, if one knows what they’re doing (I don’t), one can easily safely discharge, or simply avoid, the dangerous capacitors. Also, I’d guess that one is more likely to just get a nasty shock then to get killed – not that I’d want to risk it.

Here are the TV repair safety guidelines from

In short: If you don’t innately understand why an unplugged TV is dangerous, do not attempt to repair one!

Note that the coax input on a TV can go bad for a lot of reasons. On my JVC, the antenna module went out right within just a few years. Turns out to be a common problems for those JVC models. A replacement module is quite expensive and requires non-trivial soldering skills. So I’ve been using just the RCA inputs for several years. I also have an older set where it appears that there’s a problem with the antenna connection (snowy picture on weak signals) but is really due to a problem with the High Voltage and the HOT. Hardly an easy fix in many situations.

As to switches: I used to use a 2 input switch from RS but now use a 4* input Philips that I got from Lowes. On the later: RCA-in only connects to RCA-out and S-Vid-in only to S-Vid-out. There is no crossover.

*Digital cable, DVD, VHS and Beta!