DOES anyone have TV hardware knowledge ? get in here!

Discussion in 'OT Technology' started by Mr Bruce Wayne, Aug 27, 2006.

  1. my 50" phillips tv shuts off randomly(?) sometimes and wont turn back on some of the time. when it does work, its perfect.

    could this be overheating? do tv's have fans ? any ideas as to possible problems so i can do some of my own research

    bought it second hand so i has no warranty, only 5 years old
     
  2. Peyomp

    Peyomp New Member

    Joined:
    Jan 11, 2002
    Messages:
    14,017
    Likes Received:
    0
    Emmet Brown can help you. Just wait.
     
  3. Stilgar1973

    Stilgar1973 New Member

    Joined:
    Aug 12, 2006
    Messages:
    8,533
    Likes Received:
    0
    Sounds like when the power supply went up in my TV.
    What kind of TV is it? If it is a cathode ray (traditional) TV then I strongly suggest that you don't open it up. There are exposed wires in there that carry something like 60,000 volts of electricity - and they are very capable of holding the current after the set has been unplugged for a good amount of time.
     
  4. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    capacitors.
     
  5. Schproda

    Schproda New Member

    Joined:
    Jul 9, 2006
    Messages:
    442
    Likes Received:
    0
    Location:
    Memphis, TN
    The wires are not exposed, however I believe the 50" wouldn't be CRT but projection screen. A electrolytic cap that bleeds down could cause this to shut off, but then the power supply and a few other things could too. Take it somewhere and let them fix it.
     
  6. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    lol...wires don't store charge...that's done by capacitors and yeah, TVs have high voltage capacitors that can hold their charge YEARS after the power is off. That's why if you ever see a TV or Computer Monitor at a junk yard, be very careful...the voltage can be deadly.
     
  7. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    for the record, voltage does NOT kill.

    Current kills!
     
  8. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    haha yep....oops you caught me

    This is why I know I really don't want to be an EE cuz I lack the desire for precision in this discipline.
     
  9. MAD PUNK inDC

    MAD PUNK inDC Sic Semper Tyrannis

    Joined:
    Mar 16, 2000
    Messages:
    86,393
    Likes Received:
    1
    Location:
    the machine
    sounds like a classic problem with the flyback transformer. Voltage will leak and then short out, causing the TV picture to shut off. Question? Does the TV power light still stay on, but everything else shut off? If so thats your problem. It was really common on the Trinitrons going all the way back to the 80s.
     
  10. Schproda

    Schproda New Member

    Joined:
    Jul 9, 2006
    Messages:
    442
    Likes Received:
    0
    Location:
    Memphis, TN
    Would the 50" TV be CRT? I'm being serious cause I've never had to have one open. If it isn't, then it probably doesn't have a flyback transformer then, right? The horizontal circuitry is controlled by another..planar or something if it isn't CRT. I could be wrong, but that's just what I'm thinking. But a FB wouldn't make the TV lose power.
     
  11. MAD PUNK inDC

    MAD PUNK inDC Sic Semper Tyrannis

    Joined:
    Mar 16, 2000
    Messages:
    86,393
    Likes Received:
    1
    Location:
    the machine
    some projection TVs are CRT, and yes a problem with the flyback most certainly would shut the TV down. Sony's have had this problem for 20 years.
     
  12. RyanL

    RyanL OT Supporter

    Joined:
    Nov 30, 2004
    Messages:
    4,584
    Likes Received:
    0
    Location:
    St. Paul, MN
    I have the exact same problem with a big screen mitsubishi TV, haven't figured it out yet
     
  13. DatacomGuy

    DatacomGuy is moving to Canada

    Joined:
    Oct 14, 2002
    Messages:
    16,546
    Likes Received:
    0
    Location:
    Tampa, FL
    Yes, definitely don't open it up.
     
  14. deusexaethera

    deusexaethera OT Supporter

    Joined:
    Jan 27, 2005
    Messages:
    19,712
    Likes Received:
    0
    You can take a million volts and be fine, but 6 amps across the chest and you're done for.
     
  15. Schproda

    Schproda New Member

    Joined:
    Jul 9, 2006
    Messages:
    442
    Likes Received:
    0
    Location:
    Memphis, TN
    One tenth of an amp will fork someone for life. :)
     
  16. deusexaethera

    deusexaethera OT Supporter

    Joined:
    Jan 27, 2005
    Messages:
    19,712
    Likes Received:
    0
    I'm pretty sure I've gotten hit with that much during my adventures in amateur electronics as a kid. Maybe that explains a few things.

    Seriously though, it really does depend where the electricity passes through. People might be made of water, but the majority of the current is going to pass through the most direct path from contact to ground. People who get hit by lightning and live are usually lucky enough to have the electricity pass through a single side of their body, instead of diagonally.
     
  17. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    From what I understand, the ability of electircity to stop your heart has more to do with it canceling out your body's own electrical signals then where you the electricity strikes you.

    It was explained to me that the electricity that makes our hearts beat, travels in a sin wave and if the current received matches the opposite of that sin wave (thereby canceling out our bodies electrical wave), then a very low dose of amps can kill.

    But it's entirely possible that I'm full of shit. :)
     
  18. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    change "entirely possible" to "most definitely true"
     
  19. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    This was explained to me by a physicist...care to clarify my confusion?
     
  20. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    A/C 2-phase travels in a sin wave.

    However, 2-phase is not itself deadly. The fact that it follows a sin wave has NOTHING to do with it's ability to be lethal.

    As an example, there are documented cases of electrocution with as little as 42V DC at 100mA -- which does NOT travel in a sin wave, yet still resulted in death.
     
  21. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    You do realize that the waveform determines A/C 2-phase, 3-phase, or DC? Right? And that the only facts from the wave form that can be gathered are period (frequency) and amplitude (voltage) both of which have absolutely NO CORRELATION to the lethality of a shock!
     
  22. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    Ok...so it doesn't travel in a sin wave...sue me.

    The idea of very little current cancelling out the electricity getting to the heart was my point.
     
  23. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    current can't "cancel out" other current. That's not how anything works. Go read a freakin "basic electricity" book.
     
  24. Coottie

    Coottie BOOMER......SOONER OT Supporter

    Joined:
    Jun 6, 2006
    Messages:
    32,407
    Likes Received:
    0
    Location:
    OKC
    *sigh*

    Ok...so perhaps I should be more accurate with my wording.

    The canceling out idea was how it was explained to me as an analogy for effectively how it happens that someone receives a 100mA shock but still ends up dying. Jeez, so i'm not an EE and have no desire to be.....sue me again.
     
  25. P07r0457

    P07r0457 New Member

    Joined:
    Sep 20, 2004
    Messages:
    28,491
    Likes Received:
    0
    Location:
    Southern Oregon
    wait wait wait, you somehow think that it's not 100% your fault for being a dumbass and posting misinformation in dozens of threads today?

    tool == you.

    100mA is enough current to kill because that's all the current required to force your heart to spasm, and the walls of the heart muscle convulse uncontrollably.


    Explain in ANY capacity how "canceling out" is even remotely an accurate analogy.
     

Share This Page