If you have eliminated other possibilities such as electromagnetic
interference from nearby equipment or a faulty video cable or problems
with the video input (e.g., cable or VCR) - then noisy or fluctuating AC
power may be a possibility. However, most modern TVs usually have well
regulated power supplies so this is less common than it used to be. Then
again, your TV may just be overly sensitive. It is also possible that
some fault in its power supply regulator has resulted in it becoming more
sensitive to small power fluctuations that are unavoidable.
|NotTaR of Television Sets : Jittering or flickering due to problems ..
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.
I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.
<< Wiring transmitted interf.. |
| TV blows fuses or trips b.. >>
One way to determine if the problem is likely to be related to AC power
is to run the TV on clean power in the same location connected to the
same video input. For example, running it on an Uninterruptible Power Source
(UPS) with the line cord pulled from the wall socket would be an excellent
test. The output of the UPS's inverter should be free of any power line
noise. If the TV's image has now settled down:
- Large appliances like air conditioners, refrigerator, or washing machines
on the same circuit might cause significant power dips and spikes as they
Plugging a table lamp into the same outlet may permit you to see any obvious
fluctuations in power. What else is on the same circuit? Depending on
how your house or apartment is wired, the same feed from the service panel
may be supplying power to widely separated areas.
- For some unfathomable reason, your TV may just be more sensitive to
something about the power from the circuit in that room. There may be
nothing actually wrong, just different. While unlikely, a light dimmer
on the same circuit could be producing line-conducted interference.
If you have a multimeter, you could at least compare the voltages
between the location where it has problems and the one where it is
happy. Perhaps, the TV is sensitive to being on a slightly
different voltage. This might only be a problem if some circuitry
in the the TV is marginal in some respect to begin with, however.
- There could be a bad connection somewhere on the circuit. If your house
has aluminum wiring, this is a definite possibility.
Try a table lamp since its brightness should fluctuate as well. This
should be checked out by a competent electrician as it represents a real
An electrician may be able to pinpoint the cause but many do not have
the training or experience to deal with problems of this sort. Certainly,
if you find any power line fluctuations not accounted for by major
appliances, on the same circuit this should be checked by an electrician.
<<Wiring transmitted interf.. |
| TV blows fuses or trips b..>>