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Old 08-21-2017, 07:19 PM
Ed in Tx's Avatar
Ed in Tx Ed in Tx is offline
Zenith Walton My 1st TV
 
Join Date: Nov 2008
Location: DFW
Posts: 1,414
Quote:
Originally Posted by Adam View Post
The Zenith VR300... picture gets vertically jittery sometimes. It will usually go away by itself in less than a minute, or if I rotate the tracking control back and forth.
Probably the entry and/or exit tape guide rollers need a tweak. Those sometimes come loose even with the tiny hex set-screw they have.

If you dare, you can try and do that without an o'scope. If you do have a scope you would need the service manual to find the test points to hook up to. Start by marking the metal tops of the guide rollers toward the front with a mark from a felt tipped pen so you can get back where you started. Then play a known good tape and adjust the tracking control until the picture is noisy. If there's more noise at the top of the picture adjust the left tape entry guide next to the drum. If there's more at the bottom adjust the opposite right exit guide. Go back and forth until it's equal noise top to bottom as you adjust either side of the tracking control.
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