No, not rare at all! Heck, Just the other day my Zenith Chromacolor was jittering horizontally, and it was just low on hydraulic fluid in the beam swinger. You know; it started getting air bubbles and made the hydraulic ram shudder as the beam swinger was going back & forth. And let's not forget how Steve D's CTC-5 got low on lighter fluid in May and the pilot light in the channel window went out
Charles