Where the TV has a remote control (which most do nowadays), there needs to
be some source of voltage(s) for the remote receiver, microcontroller, and
other circuitry that watch for the 'power on' commend. These sets are never
|NotTaR of Television Sets : Standby power supplies
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The standby supply may consist of:
- A low voltage power transformer feeding one or more sets of rectifiers,
filter capacitors, and possibly regulators.
A power surge could cause the primary of the transformer to open up.
There may also be a thermal fuse under the outer layers of insulation
which blew either due to overheating or a power surge. However, if the
primary is open, it is best to replace the transformer rather than
attempting repair it.
- One or more voltage dividers connected directly to the AC line feeding
rectifiers, filter capacitors, and possibly regulators.
Open resistors and dried up capacitors are common failures since the
resistors are often not rated adequately and run hot, in close proximity
to the capacitors.
- A portion of the main (switchmode) power supply that runs all the time.
Failures could be almost anything that would affect normal operation of
the power supply as well as problems with the control circuitry.