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NotTaR of Television Sets : Power-on tick-tick-tick or click-click-c..
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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.
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A variety of power supply or startup problems can result in this or
similar behavior. Possibilities include:
- Lack of startup horizontal drive - see the section:
Startup problems - nothing happens, click, or
tick-tick-tick sound. The main regulator is cycling on overvoltage
due to lack of load.
- Excessive load or faulty power supply cycling on its overcurrent
protection circuit.
- High voltage shutdown, or some other system detecting an out of regulation
condition. However, in this case, there should be some indication that the
deflection and HV is attempting to come up - momentary whine, static on the
screen, etc.
- A dried up main filter capacitor or other filter capacitor in the low
voltage power supply that is producing an out-of-regulation condition
until it warms up. A bad filter capacitor on the output of a series
regulator may result in excessive voltage and subsequent shutdown.
- A problem with the microcontroller, relay or its driver, or standby
power supply.
One possible test would be to vary the line voltage and observe the
set's behavior. It may work fine at one extreme (usually low) or the
other. This might give clues as to what is wrong.
Also see the section: Dead TV with periodic
tweet-tweet, flub-flub, or low-low voltage.