View original (French)

Sharp Aquos won't turn on

BJ69690 Posted messages 5 Status Member -  
BJ69690 Posted messages 5 Status Member -
Hello, please excuse me, I am new to this forum

I have a SHARP LC-50LE751E TV that won’t start: the blue chevron lights up, it briefly turns red when I press a button on the remote, but there’s no image or sound. Inside, there are no swollen capacitors (no excessive ripple on the scope), nor burned components. I have correct power supply voltages on the J224 connector between the power supply and the main board; however, I don’t know if these levels are okay: PSon = 3.3V, BLon=0, Pwm=3.6V.
What do you think, knowing that I have already looked through this forum and did not find an answer to my problem? Thank you in advance for your help!

Configuration: Windows / Chrome 49.0.2623.112

4 answers

  1. Anonymous user
     
    The television may have gone into safety mode. The causes are numerous.

    Among your searches, do you not see any cold solder joints?
    A good solder has a shiny appearance, a cold solder has a dull appearance.
    --
    People who fight can lose. People who do not fight have already lost. (Bertolt BRECHT)
    1
    1. BJ69690 Posted messages 5 Status Member
       
      Thank you, but I just did a complete visual check under binoculars without success. In any case, thank you for your help!
      0
      1. Anonymous user > BJ69690 Posted messages 5 Status Member
         
        In our time, televisions were a bit more repairable; now it's more complicated. Yesterday, I took one to the recycling center. It's a shame; it was playing sound at 2 x 15 watts RMS.
        0
    2. Andy31200 Posted messages 26918 Registration date   Status Moderator Last intervention   12 200
       
      We're not going to bring up the story of the rotors again, are we?
      0
      1. Anonymous user > Andy31200 Posted messages 26918 Registration date   Status Moderator Last intervention  
         
        Before, we mainly worked with diagrams. We knew where we were going.
        0
    3. BJ69690 Posted messages 5 Status Member
       
      Exactly! I was trained in the 80s, troubleshooting was a matter of logic with measurement readings that allowed for pinpointing specific components, which were also easier to desolder and replace compared to today's ultra-fine pitch! If only we could still find the boards on a standard exchange basis! Well, we have to keep up with the times, but it's true that it hurts the heart to see this waste!
      0
  2. Andy31200 Posted messages 26918 Registration date   Status Moderator Last intervention   12 200
     
    Hello and welcome to this forum,

    Not sure if this is it but worth a try:
    It may be an issue with the electrical overload of the TV's protection circuit;
    The solution is very simple:
    You need to unplug the power cable and connect the two prongs of the plug together (short circuit with an electric wire or a piece of wire) for at least one hour to allow the protection circuit to discharge.

    --
    I call a spade a spade *
    *in French in the text
    0
    1. BJ69690 Posted messages 5 Status Member
       
      Thank you for your response, but after trying again, it's the same!
      0
  3. Andy31200 Posted messages 26918 Registration date   Status Moderator Last intervention   12 200
     
    For me, it’s the devil...;-)

    --
    I call a spade a spade *
         *in French in the text
    0
  4. BJ69690 Posted messages 5 Status Member
     

    Hello

    I'm still having the same problem with the Sharp TV.

    I've changed all the boards (power supply, signal, T-con, inverter...) and I'm still facing the same issue.

    I just ordered the sensor control board (power on/off + controls) without too much hope!

    I'll keep you updated; if the same defect persists, I'll have to check the LED strips with the great automatic tester that has already served me multiple times!

    I’ll get back to you soon.

    0