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Dead TVs

Discussion in 'Electronic Repair' started by tundra, Aug 22, 2006.

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  1. tundra

    tundra Guest

    Friends of mine have recently had 2 new TVs go out within 6 months or so of
    each other. Both were covered by warranty but I wonder if this is somehow a
    voltage problem. First one was a crt tube type and the tube burned out after
    1 1/2 years. Replaced it with an LCD which lasted only 3 months. They live
    in a small town out in the boonies so I don't know if their power signal may
    be poor. Any recommendation on how check this? Can electricians measure
    voltage fluctuations? They don't have a good surge protector or power
    conditioner but they didn't have one on their old tv for decades so they
    figured they didn't need one. Are newer tvs more susceptible to voltage
    irregularities? Anybody have an opinion on the value of a surge protector on
    a tv? are things like power consoles (like a Belkin PF30 Power Console)
    worthwhile
    insurance?
    SL
     
  2. Guest

    A CRT burning out is most unlikely. I've never come across it or even
    heard of it.

    I think this is, while possible, not the most likely explanation.

    If youre on mains, their value is zero. For private generator supplies
    theyre important, but hardly anyone runs electronics off a private gen.


    NT
     
  3. Make and models?

    There are a lot of poorly made TVs out there. Bad power wouldn't cause
    the CRT to go bad.

    --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
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  4. Yukio YANO

    Yukio YANO Guest

    Consider a "Floating Neutral" !
    Can happen on ANY 110/220 grounded Neutral installation.
    Will cause as much as 220 volts to appear on a normal 110 outlet.
    This is NOT a line surge, but the end result is the same !!!
    The most obvious symptom is lights that brighten and dim momentarily as
    other loads cycle on and off, refrigerators, microwaves, air
    conditioner, washers but not Dryers (runs on 220) and does not use the
    Neutral except for the Dryer motor which runs constantly during the
    drying cycle.
    Yukio YANO
     
  5. Or a thousand other things, including just garbage quality TVs to begin
    with! :) It's unlikely for any power problem to kill a picture tube.

    Need more info. Make and model would do for a start.

    --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
    Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
    +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
    | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name AND either lasers or electronics is included in the
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  6. Ken Weitzel

    Ken Weitzel Guest

    Hi Sam...

    I agree, but the op said "the tube burned out"; which could
    mean just about anything...

    The set died, the picture disappeared, the raster disappeared,
    etc...

    Not necessarily or even likely that it "kill(ed) the picture tube" :)

    Take care.

    Ken
     
  7. Yeah, I guess that could very well be. :)

    "My car doesn't go anymore so it must be a dead engine." :)

    --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
    Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
    +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
    | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name AND either lasers or electronics is included in the
    subject line. Or, you can contact me via the Feedback Form in the FAQs.
     
  8. b

    b Guest

    tundra ha escrito:
    When you say new tvs, you need to give us the make and model if
    possible.
    chances are, the sets weren't much good to begin with, seems the norm
    these days of disposable electronic consumerism.... SO many people tend
    to be guided by shiny silvery appearance and low price rather than
    build quality or brand reputation. Then the chickens come home to roost
    when the things crap out after the guarantee expires... so then out
    they go and buy another, new, equally shoddy piece of crap to replace
    it with!

    sorry, rant off now! ;-) no offence intended to the OP, just my pure
    speculation based on experience....
    -B
     
  9. Some modern DMMs can measure max - but a TV should run from 90 - 140 VAC OK.
    Cheap and don't hurt - usually.
     
  10. Guest

    Plug-in protectors are cheap? Hardly. They cost typically tens of
    times more money per protected appliance. Since they are missing that
    short and dedicated earthing wire, then plug-in protectors may even
    provide a surge with more destructive paths through an adjacent
    appliance.

    We traced path of a surge that damaged networked and powered off
    computers. Confirmed that path by replacing ICs on the board and
    restoring all machines. A protector does not stop, block, or absorb
    surges. It is called a shunt mode device. It shunts - either to earth
    ground or into adjacent appliances. They simply distribute a surge to
    all other wires. If one of those wires is not the short connection to
    earth, then a protector may shunt that surge to earth via a protector.

    Effective protectors make the 'less than 10 foot' connection to
    earth. Protector earths transients that would otherwise overwhelm
    protection already inside appliances. Any protection that would be
    effective on that computer power cord is already inside the computer.
    Protection that remains effective if transients are not permitted
    inside the building.

    They are called 'whole house' protectors. Sold in Home Depot, Lowes,
    and electronics supply houses are effective products from Square D,
    Siemens, Cutler-Hammer, Intermatic, Leviton, and GE. Not mentioned are
    products sold in Radio Shack, Walmart, Sears, Staples, Circuit City,
    Kmart, or Best Buy. Effective protectors have that dedicated earthing
    wire to connect protector to protection. Protection is the most
    critical component in any protection system: earth ground. Just
    another reason why the home earthing may need be upgraded to post 1990
    National Electrical Code requirements.

    So where in those numerical specs does the plug-in manufacturer even
    list each type of transient AND provide numbers for that protection.
    Notice no mention of protection in their numerical specs. And one
    would call that cheap? Yes. So cheap to enrich its manufacturer and
    yet provide no effective protection. It don't hurt the manufacturer.
    And it also don't claim to provide that protection. Listed is
    effective protection that costs less money. Defined are ineffective
    plug-in protectors with hyped names and yet don't even claim to provide
    protection in their numerical specs.

    Insurance with a plug-in protector? You wish. Review details in its
    warranty. Chock full of exemptions. One even implied that if a surge
    protector in the building was not manufactured by them, then warranty
    is void. The list of exemptions like this are numerous. Warranty on a
    protector only exists when one forgots to read details.

    Effective protector makes a 'less than 10 foot' connection to earth.
    Every homeowner should consider this many times less expensive and so
    effective solution.

    Meanwhile none of this is about low or high voltage. Transients
    (volts of 10 or 100 times higher) that occur in microseconds have
    little relationship to voltages that make minor changes in seconds or
    milliseconds. Solutions to high or low voltages (140 to 90) involve
    other solutions; other devices. Low voltages must never damage
    electronics. Appliances must also withstand high voltages such as 140,
    170, and 400 without damage depending on time.

    Before discussing voltage irregularities, first define each with
    numbers - voltage and time. A surge protector complete ignores when
    120 volts climbs to 200 volts. See its box. Let-through voltage is
    maybe 330 volts.
     
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