Static problem

Well, I pulled the tuner unit out of the set, and what immediately caught my eye were tiny "scratches" in the underside of the circuit board. It looks like someone was careless in the manufacturing process, as these are everywhere, crisscrossing the traces and the board. In a few places I noticed some of the traces were covered in a thin layer of solder. No doubt the scratches in those areas were so bad they broke the circuit, hence the need for the solder.

I cannot believe something made in the USA would be put together so sloppily.

Tim

Why ??

It's been repaired before - possibly on the production line. Those cuts are made for testing.

Huh?

Well, I patched the worst of the traces and the TV set didn't act up, but I'm not going to declare a victory until I've used the TV set for a while and observed its behaviour.

Supposing my problem isn't gone, where would I look next?

The tuner part was surprisingly easy to remove and disassemble, and other than the scratched traces nothing looked out of the ordinary. No bulging caps, scorch marks, loose wires, etc.

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I fear this might take the topic on a path I never intended it to go, but anyway.....

In my experience, American products have been well built (barring cars) and last a long time, such as old radios, TV sets, furniture, etc.

I personally avoid chinese products because their quality is so poor it's a miracle anything from there made it to the US in one piece, let alone work for 5 minutes after its arrival.

In a nutshell, I expect (and these expectations have mostly been met) American products to be far superior to those cheaply made in sweatshops in foreign countries. If my TV were made anywhere else, I would not be surprised with my findings.

Tim

The 'static' is probably better known as snow. At this point you really need a signal source you can inject into the IF strip to localize the problem.

A good start is to resolder every connection between the board inside the tuner and the metal shield. Bad connections tend to develop there due to the thermal expansion of the shield every time the set is used. Most of the Zenith sets I've seen from that time period needed to have the tuner resoldered. The ones around the edges are usually the problem, but don't overlook the connections in the middle of the board. Andy Cuffe

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