S.E.R. FAQ
Home
Search
NotTaR of Television Sets : Horizontal lock lost                    
 Copyright © 1994-2007, Samuel M. Goldwasser. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied: 1. This notice is included in its entirety at the beginning. 2. There is no charge except to cover the costs of copying. I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.

        << TV will not sync |  Index  | Insufficient width (witho.. >>

Horizontal lock lost

A TV which loses horizontal lock when changing channels, momentarily losing the signal, or switching inputs may have a horizontal oscillator that is way out of adjustment or has drifted in frequency due to aging components.

Note that the characteristics of this are distinctly different than for total loss of sync. In the latter case, the picture will drift sideways and/or up and down while with an off frequency oscillator, the torn up picture will try at least to remain stationary.

This could be a capacitor or other similar part. Or, the oscillator frequency may just need to be tweaked (particularly with older sets). There may be an internal horizontal frequency adjustment - either a pot or a coil - which may need a slight tweak. If a coil, use a plastic alignment tool, not metal to avoid cracking the fragile core.

A schematic will be useful to locate the adjustment if any or to identify possible defective parts. Try a large public library for the Sams' Photofact for this set.