Sony TV powers off automatically after few secs

[Ann Onymous]

My Sony KV20S30 20" TV has recently gone on the fritz. When I turn on
the power, I hear the initial powerup click, followed by the usual soft
metallic "tunk" (what is that sound, anyway?) one second later; then,
after 2-3 seconds, it quietly powers off (I can just barely hear the
speakers turn off). This sequence repeats itself as often as I press the
power button. It's never on long enough for a picture to appear.

I've tried unplugging it for hours or days, but nothing resets. When my
DVD had the identical problem, that seemed to fix it.

Anything I should know or try before taking the TV in for service?

 

[RubbishRat]

My Sony KV20S30 20" TV has recently gone on the fritz. When I turn on
the power, I hear the initial powerup click, followed by the usual soft
metallic "tunk" (what is that sound, anyway?) one second later; then,
after 2-3 seconds, it quietly powers off (I can just barely hear the
speakers turn off). This sequence repeats itself as often as I press the
power button. It's never on long enough for a picture to appear.

I've tried unplugging it for hours or days, but nothing resets. When my
DVD had the identical problem, that seemed to fix it.

Anything I should know or try before taking the TV in for service?

This sort of behaviour can be baffling but what's happening is, the onboard
computer is detecting a problem with one or more of the power supply rails.
You can switch it on and off till you grow old, but as long as the detected
parameter is out of spec the TV will not be allowed to start up. If you
really want to find out what's going on and maybe even learn how to fix it,
read the pages of this web site http://www.repairfaq.org but be warned
unless you have a genuine interest in electronics, it's uphill work. in fact
even if you do have a genuine interest it's still pretty steep :^)