vtech |
Posted: Sat Jun 10, 2006 9:24 am Post subject: |
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In general, with SMPS there are switched & unswitched lines. Unswitched lines are usally one or two unregulated supply lines that will run as soon as the unit is plugged in, however the switched lines are controlled by means of a "power on" signal pin that comes from the syscon. It's possible that your unswitched lines are either low or loaded down--therby hearing the ticking sound. Or it can easily be related to dried up electrolytic caps causing too much AC floating throughout the circuit. |
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