1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Panasonic TH42PW5 shuts down LED 2 blinks

Discussion in 'Plasma TVs' started by szillat, Mar 14, 2005.

  1. szillat

    szillat
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    My two year old Panasonic TH42PW5UZ worked fine for 18 months. Then it started shutting down after a few hours with the power LED blinking 2 times. Being in the caribbean islands, getting service was not an option. No one from Panasonic or dealers would help on the phone, so I ordered the Service Manual. While waiting for it to arrive, I disassembled the TV, blew out all the components with compressed air, and got a spare screw out of the D-board for my trouble -- no doubt lost in the case during assembly. Upon reassembling the TV, it worked fine for four months more. Now it is exhibiting the same problem, but it will only run for 5 to 30 minutes before shutdown and then it needs to cool down for some time before it will come back on at all. The two blinks on the LED according to the Service Manual mean that the SC or SS or C boards are bad. The SC and SS boards have diagnostic LEDs that light up OK. The C boards don't so I can't tell if they are really bad or not. Since it will turn on and work for SOME time, I suspect the problem may be similar to others I've read about in which a diode on the P board (power supply) is over-sensitive and shuts the unit down in anticipation of a problem. Unfortunately, no service techs want to speculate. Cost to ship the unit for repair is up to $800 round-trip, plus $350 for service, plus parts. I'm thinking I will buy the two C-boards for $150, but they won't let me order them on-line without an authorized dealer! They WILL let me order parts that cost $650 to $1700 WITHOUT authorization. This leads me to believe that the Service Manual suggesting that the C-boards are at fault may not be the whole story. Any feedback from your personal experience would be appreciated.
     
  2. fatherted

    fatherted
    Standard Member

    Joined:
    Mar 6, 2005
    Messages:
    87
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Location:
    Hampshire
    Ratings:
    +0
    Can you get hold of "freezer spray" ? It's a aerosol can of gas that will cool things rapidly. RS / Farnell etc sell it in the UK, but can you source it locally? (plumbers also use it to freeze pipes). RS part number 329-2713. www.rswww.com

    If you can, get the screen in a state where it won't startup and then choose a board and spray the components GENTLY to lower the temperature - re-power it and see if it will start up, if it will, then use a hair drier to raise the board temperature GENTLY, then it will fail (hopefully) - if not move on to the next board you suspect.

    After a bit of practice you will be able to isolate the actual component which is heat sensitive then you can decide what to do from there. It might be repairable locally.

    This is the same method I have used to fix PC's and such like.

    Of course I don't need to tell you the extreme dangers of spraying things on boards in live equipment do I ? Don't work unsupervised !....and if you get stuck there are about 2000 board members who will reluctantly fly out to assess your problem
     
  3. szillat

    szillat
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Tried the cooling/heating method you discussed to no avail. Tried turning all on-board power taps 1/4 turn down and 1/4 turn up, cycling power between each setting, also to no avail. After trying this adjustment on a dozen potentiometers on three boards, I turned off the set and walked away to try to get a service company to buy me the C1 and C2 boards -- no luck due to the holidays. Turned the set on today and it works fine, at least for now.
     

Share This Page

Loading...