Announcement

Collapse
No announcement yet.

Roadstar 7" LCD-7111KL - Dead - Solution - LCD picture problem

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Roadstar 7" LCD-7111KL - Dead - Solution - LCD picture problem

    Hello everyone!

    This 7" TV was operated as a secuirity monitor for many years and was dead. No led no reaction.

    The main problem was with Q7 a SOT-23 AO3400 mosfet which was shorted.
    I replaced that part with IRLML6244TRPBF.

    Some capacitors had high ESR so i replaced about 4-5 with such a problem.

    Upon putting everything back together the image ofo LCD has "lines" and seems to be missing a colour or something. (Check images). If i applied less pressure or "twist" the case it did disappear for some time. I thought it could be the LCD's flex but moving it around doesn't seem to cure the problem. Now the problem is always there.

    I ended up replacing almost all electrolytic capacitors (30+) but problem still there. Do you think it is a problem of the LCD panel?

    Voltages are:

    +33V = 32.5V
    +15V = 15V
    +8V = 8.1V
    -15V = -16.1V (A bit off)

    IC5 operates quite hot at around 70 celcius.

    P.S. Sorry i could not find a photo of the bottom of the PCB. If it is needed i will dissasemble the TV to get some more pics.

    Thanks for any input!
    Attached Files

    #2
    Re: Roadstar 7" LCD-7111KL - Dead - Solution - LCD picture problem

    Here is a good pic of the bottom side of PCB, in case the others didn't help.

    Also i noticed that IC5 (main chip) gets hot even without the LCD panel connected.

    Thanks!
    Attached Files

    Comment


      #3
      Re: Roadstar 7" LCD-7111KL - Dead - Solution - LCD picture problem

      Problem with image was originating from the smd FPC connector of the LCD.

      It needed some reflowing as connection was not good.

      Comment

      Working...
      X