Help! I just blew-up the video-in (composite) on my VCR.

[uart]

Help! I just blew-up the video-in (composite) on my VCR.

Hi I’m just trying to figure out what happened so I know what not to do again. I was trying to connect the TV out (analog) of my new Nvidia 7900GS card to my VCR video in connection.

The new card came with two “break-out” connectors for the card’s analog TV out port. One of these was a three-way “red, green, blue” component video out and the other one was a single composite video “yellow” cable. I don’t have the RGB component video inputs on my TV or VCR so I knew that I had to use the yellow composite video cable, but that dam thing wouldn’t fit into the connector on the video card. With no proper manual (as in one that referred specifically to my card and it’s connectors) and out of frustration I eventually tried the component video’s R B and G connectors (one at a time) into my VCR composite video-in but as expected to no avail. (I know this was silly but the “generic” manual referred to connecting the card to composite video and since the supplied breakout connector didn’t seem to fit I took a desperate punt on the composite signal maybe sharing one of the RBG component outputs).

I don’t know if doing this could have damaged the composite video-in of my VCR but the VCR seemed to function normally afterward, no harm seemed to be done. I used it that night (set-top box connected through the composite video-in and it was fine). However the next day I eventually discovered that the composite-video breakout connector did in fact fit the card, it was just a much tighter connection than the other one but it did fit correctly at last (definitely no bent pins or anything here). So armed with this I went to re-connect it to the VCR video-in but this time using the correct breakout connector, but the picture came out really bad, too dark, colours wrong, distorted and breaking up. Eventually I found that it was actually the video-in on the VCR that had suddenly stopped working properly at this point (and it hasn’t worked properly since). I’ve since tested the graphics card's output on my TV (composite video in) and it’s perfectly fine.

So I can’t figure out why my VCR video-in suddenly died when I tried to connect it to the video card. If it had of happened yesterday when I connected it to the incorrect RGB signals then I could understand it but why did it wait until I connected it properly before dieing. Perhaps it was mortally wounded the previous day but somehow kept working until just this moment, I don’t know.

BTW. Does anyone know the voltage specification for “component video” as opposed to composite video. Is it so different that it might have damaged my video-in circuitry?

[jman98]

Well, the good news is that I don't see how what you did could have damaged your VCR. Component cables are not magical special cables. I am actually using some cheap RCA type cables usually used for composite video. I have 3 of them connected between my HD TV and my DVD player and I am getting excellent results. I did not buy any special expensive RCA cables either - I used 3 spares I had lying around the house. The connector should be the same between component and composite. There are no special voltage requirements for component video.

Your VCR may just be showing its age. It could just be a fluke that the composite blew up at this time. Maybe you pressed too hard when connecting the cables and somehow damaged it. However, using a "component" cable as a composite cable did not in itself damage your composite input on the VCR.

[Signal]

Composite or Component don't go much beyond 1v peak to peak (usually 1vpp on the Y and 0.7vpp on the R-Y, B-Y component lines).

As jman98 said it shouldn't have done what it did based on that and could have been for the reasons they stated.

But there is also always a good chance there's was/is a good grounding problem.

BTW -Did you have your cable tv hooked up to the vcr at the time?

[uart]

Thanks for the replies guys, sorry I couldn't respond earlier but I'm on a different time zone.

However, using a "component" cable as a composite cable did not in itself damage your composite input on the VCR.

Hi jman, I think you've got the wrong idea about what I did. It wasn't just a wrong cable. It was the actual wrong output from the card that I connected, not just the wrong cable. That is, I connected the actual component video outputs (R B and G) of the card (one at a time) to my composite video (Y) input! As for pushing too hard and breaking the connector, that's not the problem because there are two "video-in" connectors on the VCR (AV1 and AV2, one front and one rear). I only used the front one during the incident but both off them stopped working properly. I'm pretty sure it must be something common to both, like a buffer amplifier or something, that got blown.

But there is also always a good chance there's was/is a good grounding problem.

BTW -Did you have your cable TV hooked up to the vcr at the time?

Hi signal. I was also thinking perhaps a grounding problem, though I have connected AV signal between my computer and TV/VCR in the past without any issues and the grounding has been the same. Also I don't have cable TV, only "free to air", so that simplifies the grounding issue.

BTW, The VCR still works otherwise. That is, it plays videos and I can watch/record TV through it's internal tuner. It's video outputs still work, it's only the two video inputs (AV1 and AV2) that have stopped working.

Anyway thanks for the reassurance that component video is no greatly different voltage. I guess it must have just been bad luck or a fluke or something. Time for me to get a new VCR.

[Video Head]

Was the power off on both the VCR and your computer when you made these connections?

VH

[uart]

Was the power off on both the VCR and your computer when you made these connections?

No I think the VCR was powered on, but is it actually necessary that the power be off when you plug an AV connector?

[Video Head]

Yes. These are not "hotswap devices". Always power off a video device when making connections. Just be thankfull that your VCR's input BUS is the only casualty...your video card could have gone too.

Your problem may have also been caused by plugging component signals into a composite input. Although you where only plugging in one component at a time, component can carry HD frequencies as well as SD frequencies. Your VCR is only designed for a standard SD frequency. If your component output is set for an HD high-frequency output signal this could cause a failure. People have killed TV's connecting their computer's component output to the component input of their SD TV and setting the frequency too high.

VH

[uart]

Your problem may have also been caused by plugging component signals into a composite input. Although you where only plugging in one component at a time, component can carry HD frequencies as well as SD frequencies. Your VCR is only designed for a standard SD frequency.
VH

Thanks for the info VH.

I'm tending to think that it was the act of connecting component video that did it. I'll take note of what you said about hot-plugging but for the record I've hot-pluged composite video "about infinity" times before and never blown anything.

My personal best theory at the moment is that I killed something in the front AV2 input at the time that I incorrectly connected the component video but I didn't notice the problem that night because I dont normally use the AV2 connector for anything else. I connect my "set top box" through the rear AV1 input so that night when I watched TV I knew that AV1 was definitely still working.

I think it was only on the following day when I actually went to use the (possibly already damaged) front AV2 input that the fault must have propagated through to a stage common to both AV1 and AV2, which has left me in the present situation.

[lordsmurf]

I don't see how this could have been damaged in the way you say.

[handyguy]

You can get another vcr from a thrift shop for $5-10 if you want to try that route.

[cd090580]

Would by easier if you could post pictures of your connectors and a picture of what's displayed on your TV when you have bad image.

[uart]

Would by easier if you could post pictures of your connectors

Is anyone else here confused about what a VCR composite video input looks like? I don't think pictures of it are necessary.

and a picture of what's displayed on your TV when you have bad image.

Ok that would be a good idea but unfortunately I can't capture it at the moment. Basically the picture is too dark, the colour is wrong showing mostly red and brown, and the sync is bad with rolling and flickering etc. You can still recognize what you're watching but it's bad enough that you'd never use it.