pulsing tv?

[vwboomer]

Lately my Toshiba seems to be pulsing sometimes. Nothing steady, and it's not a strobe effect but it does get annoying. Does this mean m bulb is on the way out? It's 2 years old, but wasn't the main tv except for the last year so probably doesn't have that many hours on it.
I really don't need another expense right now 

[DarkStaR]

When this occurs, are there any other appliances on?

Usually the bulb dims before they go.  Have you noticed?

Try a power conditioner.  Could be "dirty" electricity.

I use one of these:

[vwboomer]

The only other thing on the circuit is the fridge and 1 lamp. Weird how it just started suddenly.
It's not getting dim though, so perhaps it's just shitty signal from the cable company.

[mitt]

When this occurs, are there any other appliances on?

Usually the bulb dims before they go.  Have you noticed?

Try a power conditioner.  Could be "dirty" electricity.

I use one of these:

How do you measure "dirty power", and how do you know that power conditioner xyz made  a difference?

mitt

[Jarvicious]

How do you measure "dirty power", and how do you know that power conditioner xyz made  a difference?

mitt

It's hard to measure "dirty power" but you can generally assume that the power you use every day isn't running a continuous voltage.  Normal household wall outlets run at around 120v, but depending on the age of the wiring, how large the building is, whatever else is on the circuit, etc., that number can fluctuate from close to 130 down to 110 or so.  When it hits that low point or wavers throughout that range of voltage, it can cause excessive power build up in the capacitors in your equipment or a shortage of power.  Either way, electronics like a steady source and that's what a conditioner does.  It takes that wonky power (yes, that's the technical term) you get from any household outlet and stabilizes it.  Is the fridge on the exact same outlet, or just on the same breaker?  Unless there's a problem with the compressor on the fridge and it's pulling more than its fair share of amps, I doubt it will be causing problems.  How old is your place/outlets?  Are they grounded?  Also, I'm assuming we're talking about Tosh LCD here and not a tube TV?  It's not so much a problem with LCDs that I've found, but old tube tvs had issues with magnetic fields, i.e. speakers and cell phones and such.  I agree with darkstar, bulbs usually gradually crap out before they're gone entirely, but this doesn't sound like a bulb issue.  The bulbs have nothing to do with the image, per se, they just provide a backlight source.  You may try moving the tv to a different outlet. 

[DarkStaR]

How do you measure "dirty power", and how do you know that power conditioner xyz made  a difference?

mitt

http://www.monstercable.com/power/Monster_Power.asp

First hand, I can't confirm. I played with the demos that create interference with and with out a conditioner. And of course there was a difference.

I'll put it this way, it's a (SUPER) glorified power strip.

Most conditioners just have filters that cut out specific interference for a type of device connected to it.  All plugs are for a specific type of device (digital, analog, high power, etc.).

I mostly bought it for piece of mind considering what's being connected to it, and how much power I'm drawing out of a given outlet.  At one point I was exceeding the outlets 15amp breaker at full power (never tripped it though).

I can't confirm it will make a difference for the OP, and it's probably out of many peoples price range.  But for me it's insurance.

I will tell you this though, since I've had it (over 5 years now), I've NEVER had interference on any of my equipment (even with a vacuum cleaner running on the same circuit).

[mitt]

I work in the electrical distribution industry, and have put oscilloscopes on my wall power at home and at work - very clean, low THD.  The standards power companies use I would bet are stricter than any consumer product available.  

It is actually easy to measure power quality, if you have the right equipment.  And that was why I was asking, if before dropping a lot of money on conditioners, if people look at their actual power quality first.  I feel a lot of the conditioner sales are snake oil-ish.

Now, if you have a appliance that is a power hog, and or not running properly on the same circuit, then it could create power quality issues on that circuit, but I doubt a conditioner has enough range to compensate for it.


mitt

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[mitt]

I mostly bought it for piece of mind considering what's being connected to it, and how much power I'm drawing out of a given outlet.  At one point I was exceeding the outlets 15amp breaker at full power (never tripped it though).

FYI - Any UL labeled breaker has to hold 100% rated current at 40degrees C ambient, and trip at 135% current at 25C degrees ambient within an hour, so a 15A breaker can run probably run at 20A for half an hour or more in a standard temperature house.  It can run at 200% (30A) for probably 20 to 30 seconds, and maybe even 300% (45A) for 5 to 10 seconds.

Typically breaker magnetic instantaneous tripping starts around 600%.

 

mitt

[Jarvicious]

I work in the electrical distribution industry,

snip

You're in the electrical biz?  It was a loaded question! 

I'm running my LCD, my pc, my 110w per channel reciever, and 650w sub on the same circuit and I've never felt the need for a conditioner and everything sounds great.  I'm sure there is a bit of harmonic distortion, just not enough to hear at the volumes I normally use, then again not all of us have an Oscope at our disposal  .  Even if it is a bulb in the OP's tv that's causing the problem, it generally costs just as much to have that replaced as it does to get a new tv.  Home theater repair isn't cheap. 

[wbeck257]

lol.. 120v's...
We get about 6% on either side of 120v's. Which means we can run it up at 127v's, or as low as 113v's.

And we get a lot of claims about burning up TV's w/ high voltage -- thats why we have a closet full of power quality meters.

Call you power company -- tell them you might have a concern w/ high voltage in the house. They'll let you know whats up.

[mitt]

You're in the electrical biz?  It was a loaded question! 

Sort of.  I am genuinely interested in all things electrical, so when people have examples of bad power, I want to know.

I have heard of several examples that have caused interesting events in a house, but never an appliance failure.  One example was a house built within several hundred feet of high voltage lines.  The EMF from the lines actually "powered up" off circuits in the house.  There was an appliance that would not shut off, even when the circuit was off, because the few millivolts generated inside the wall wiring from the power lines was enough to power its microprocessor.

One thing to keep in mind, is that voltage drop across your wiring in your house is probably more significant than the voltage drop the utility is providing.  If you have 100' run of 14g in your house, and you are pulling 15A, you are dropping 10V in the wire by the time you get to the load.

mitt

[vwboomer]

House was built in 1948, and the wires for the tv outlet are original. The fridge outlet is the last on the circuit, and is physically seperate from the tv outlet.
I've never had any problems with noise from the stereo which is on the same circuit. That doesn't rule out noise on the line, I suppose. The fridge is 4 months old, and the pulsing occurs independent of the fridge running.

The tv is DLP. Since the pulsing isn't limited to certain colors, I'm thinking of maybe getting a new cable. Right now it's HDMI but I could swap to component and run it that way for a couple days to see if it makes a difference.
It's nice that it doesn't do it all the time, and irritating because it's tougher to troubleshoot 

[mitt]

I just noticed something on my new lcd tv.  It gets brighter and darker based on ambient room light.  If the room light is "medium", then the tv sometimes adjusts constantly based on  how much light it is adding to the room.  If the room is very bright, or very dim, then there is no changing brightness.

mitt