Re: TV sounds like dripping faucet when off

On Sun, 15 Oct 2006 19:31:20 -0700, Don Lancaster <don@xxxxxxxxxx>
wrote:

Paul E. Schoen wrote:
This might not be directly related to design, although possibly the
original design of the TV, so here goes..

I have a fairly old (maybe 1990) Emerson color TV which has worked fine for
all that time. A few days ago, I heard a sound that was just like a
dripping faucet, at about a one second repetition rate. I traced it to the
TV, and it seemed to be coming from the speaker. I unplugged it, because I
have heard of some TVs catching fire when their standby circuits
malfunctioned. It seemed OK later when I reapplied power, but the problem
returned some time after I turned it off.

The TV may have been damaged by the close lightning strike that I described
in early July. I also noticed soon after that happened, that there is a
streak in the center of the screen that shows an abnormally red color.

It's probably not worth taking apart and doing extensive troubleshooting,
but I just wanted to know if anyone has experienced anything like this, and
what it might be. It acts like a buildup of charge and then a sudden
discharge, but I would think the only thing powered up when it is off is
the remote control IR detector circuit. The power on circuit might trigger
a triac that could be leaky, but I hear a distinct click when the TV turns
on, indicating a relay.

I need to move the TV soon to do some remodeling. Maybe I'll take it apart
and see if there's anything obvious. Otherwise, maybe it would be safer to
just get a new TV for $200 or so. Meanwhile, I'll keep it unplugged while
not watching it.

Paul


Obviously a drain problem on a field effect transistor.

Sno-o-o-o-ort ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
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Relevant Pages

  • Re: TV sounds like dripping faucet when off
    ... Paul E. Schoen wrote: ... I have a fairly old Emerson color TV which has worked fine for all that time. ... It seemed OK later when I reapplied power, but the problem returned some time after I turned it off. ... It acts like a buildup of charge and then a sudden discharge, but I would think the only thing powered up when it is off is the remote control IR detector circuit. ...
    (sci.electronics.design)
  • Re: TV sounds like dripping faucet when off
    ... original design of the TV, ... I have a fairly old Emerson color TV which has worked fine for ... It seemed OK later when I reapplied power, ... the remote control IR detector circuit. ...
    (sci.electronics.design)