JVC D Series Horizontal Smearing on the Composite Input

[vol.2]

Originally Posted by BenM86

As far as the settings go, it's possible it's been messed with. D series TV's tend to trade hands often, so im sure the service menu has been accessed. The red push was already disabled when I got it, so someone has been in there at least once. I should at least sit down and make sure everything is set to factory based on the service manual just in case.

I did have that thought. If you can do it safely, it's a good idea to make sure everything is correct. I wouldn't change any settings that aren't explicitly called out and explained in the service menu though; in my experience, many service menus contain options that are not documented for various reasons, and they shouldn't be messed with. Sometimes it has to do with some very basic operations that would never need to be changed, and sometimes they adjust things that weren't implemented in the circuit design (optional inputs and features).

There are absolutely settings in some service menus that will remove the picture, including the service menu text itself. If that happens, you're kind of screwed.

Again, I don't know JVC stuff too well, but I've run into it in other sets.

Recapping could help, but I'd recommend getting a good LCR meter (or an ESR meter if you want to save some money) and actually checking the caps you pull out rather than doing a shotgun. Sometimes shotgunning a set will end you up in worse shape than you started. This usually happens as a result of making mistakes (pulling up pads and traces, putting in caps backwards), but it can also happen because of less obvious mistakes such as using the wrong type of cap.

And that's why checking voltages is the way to go, because it points you to an issue in the operation of the circuit at a certain point. Once you discover a wrong voltage, you can scour the parts that would effect it and that should lead you to a problem. Sometimes there are multiple independent problems, or many problems caused by a cascade failure.

Whatever you're looking for seems like it's pretty specific though, because it's only on one input. Either the settings are wrong, or something touching only that input signal path is wrong. I like those chances.

But yeah, make sure the settings are correct first.