re mysterious tv problem source llbgb utxdp dp utexas edu writes initial symptoms no picture or sound crt filament does not glow flyback ticking as described abovew discovered when hooked up the scope if strip is not putting out audio or video signals everything is making simple hz pulses horiz out transistor collector case of the to is a hz downgoing sawtooth with ca khz ring at front end guys what s going on here anyone seen this before what is happening is this you turn the tv on the horizontal output begins normal operation this powers up the high voltage and most of the rest of the circuitry a problem is sensed and the horizontal oscillator shuts down after it powers down the cycle repeats things to check first check for a shorted high power component your best bet is the vertical output transistor s or if there is one the voltage regulator the most common cause of this type of failure is too much current being drawn somewhere also look for shutdown circuits which your tv may or may not have if you can find one that is shutting down the horizontal oscillator then it shouldn t be too hard to find the problem from there
