Jeff, the 7834 (and most of the other 7000-series, the 485 and the later serial numbered 434) has a heaven-sent power supply. The "ticking" you were hearing was the sound of the switcher trying to come up but finding an imbalance on one of the many supplies in the mainframe (+50, -50, +15, -15, +5), usually caused by a short to ground, typically because of a shorted bypass or filter capacitor. Obviously, you found the problem, and the errant vertical preamp has such a fault in it.
The 7834 supply is constantly checking for all of the linear regulated supplies to be at the proper voltage, for proper primary current on the switching transformer and for zero crossing of the line voltage.
To troubleshoot a "ticking" 7000-series, just let it tick and connect a scope probe to each of the regulated supplies in turn. You should see good supplies hop up to or near their proper voltage and a bad supply won't.
Dean