TV joy

[danaeris]

So I finally sit down to watch the rest of Ghost in the Shell on the new TV and whaddaya know... we're still getting that weird fade from bright to dim, except now there's no color distortion (which helps). And there's still the occasional blue screen.

I checked and the VCR doesn't have this problem. So. There are three possibilities here.
(1) The A/V cable is broken. Anyone have an A/V cable we can borrow to test this theory? Or a spare one you are willing to give us?
(2) fenwickrysen's DVD player is broken in some way.
(3) The part of dragon_spirit's VCR which receives the signal from the DVD player is broken.

I'm laying my bets on #1. Any thoughts/helpful input?

Comments

[aaangyl.livejournal.com]

What happens if you take the DVD player out of the system entirely (including all a/v cables and unplugging it)?

[aaangyl.livejournal.com]

Err. I meant VCR, but my fingers had other ideas. Take the VCR out.

[danaeris.livejournal.com]

sadly, I do not have the right connectors. the DVD player takes s video and a/v cables. The TV only takes that connector for which I do not know a name but it connects to cable boxes or antennae. It happens that the VCR DOES have that connector.

[auros]

I'm guessing the one you don't know the name of is coaxial cable. (Pin in the middle, cylindrical shell of metal at the outside, plastic-y stuff between them.)

Next time I buy a TV, I'm definitely going to get one that takes either component video (where you actually have a separate wire for each color signal), or A/V and S-video. Using coax seems to wipe out pretty much all the improvement in video quality you get from using a DVD player.

I just checked the Evil Tangle of Doom, and at first glance it does not appear to include any spare A/V cables; not surprising, considering how many are in use running my current setup. (The PSX, N64, and computer, which doubles as my DVD player, all are hooked up to the TV through a box that takes A/V/S input.)

[auros]

Yeah, that sounds vaguely familiar. But everybody I've ever talked to in a Radio Shack, Circuit City, Best Buy, etc, has know what I said if I said "coax cable". :-)

Incidentally, I don't suppose you (or anyone else?) know what the deal is with devices that interface with coax cables having switches marked with resistance values? The typical one will have two positions labeled "75 Ohms" and "100 Ohms" (where the word "Ohms" is replaced by the capital omega symbol that generally represents Ohms). I'm guessing this has something to do with the resistive material between the two layers of metal -- resistive material of course improves capacitance across the gap, which should, as I understand it, mean a larger voltage difference can be maintained across that gap, leading to a larger posssible amplitude for the signal conveyed by varying that voltage. However, even with that guess, I have no idea what to do with those switches; I've never been able to detect any difference in picture quality based on toggling them, and none of my cables have ever come labeled with info on resistance or capacitance. It's quite puzzling. :-?

[auros]

So that would imply that if I want to figure out if I've got the wrong setting, I should flip to the highest numbered channel that actually has a valid signal in it, and compare performance on the two settings of the switch up at that high end?

Though of course, currently my highest channel is something like 16, so that might not work... I used to get up to something like 72, but I cancelled "extended basic" service, because I wasn't watching anything on it... *g*

[nytemuse.livejournal.com]

I'd offer, but my only AV cable is stereo to mono, which probably wouldn't work.
Let me know if you decide to buy a new one; I'll pick one up @ work and drop it off Sunday when I'm in SF.

macrovision

[geekosaur]

That sounds like the DVD is protected with Macrovision, a system which messes with the AGC (automatic brightness adjustment) to prevent copying.

Macrovision relies on the fact that most VCRs have cheap AGC circuits which are easily confused. This effectively prevents making good copies --- but it also screws with playback of Macrovision-protected video through VCRs even in (supposedly) "pass-through" mode. (I gather VCR manufacturers save a few tenths of a cent per machine by not implementing real passthrough, so the AGC is active even in that case.)

The simple way around it is to not play the DVD through the VCR. The more complex one is a relatively simple circuit (whose schematic is widely available, although prebuilt ones generally aren't for legal reasons) which defeats Macrovision by regenerating the AGC.

Re: macrovision

[auros]

*facepalm* I should've thought of this -- I had exactly that problem, before I stopped routing the DVD output from my computer through my VCR.

And I do have a spare A/V to coax converter box, and a spare coax switch (two inputs, one output), so if you want to try rewiring, questioner, I can provide those. :-)

DVD-VCR badness

[admiralthrawn.livejournal.com]

Many DVD players are designed to not play properly when the output is piped through a VCR, to defeat eeeeevil movie pirates. If your TV doesn't have the right kind of cable input for the DVD players output, try going to radio shack or the local equivalent, and see if they have a converter; I think there exist cheap boxes that will convert newer media cables to coax.