Announcement

Collapse
No announcement yet.

TCL 65S421 No Backlight

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    TCL 65S421 No Backlight

    I can see an image on the screen with a flashlight. Is P_ON at 2.6v acceptable or does it need to be 3.3?

    Main Connector
    1- 3.3 - BL_ON
    2- 3.3 - P-DIM
    3- 2.6 - P_ON
    4- 0 - GND
    5- 2.6 - A_DIM
    6- 0 - NC
    7- 0 - GND
    8- 0 - GND
    9- 12 - 12v
    10- 12 - 12v
    11- 12 - 12v
    12- 12 - 12v
    13- 0 - 3D_EN
    14- 12 - 12v

    I see no voltage on either side of TS2 or TS3. Is something else causing U601 to not drive TS3?

    U601(OZ9976GN)
    1- -.038 DRV1
    2- -.036 GNDA
    3- 12.1 VCC
    4- 3.28 ENA
    5- 6.01 VREF
    6- 3.285 PWM
    7- 2.159 ADM
    8- -.036 STATUS
    9- 2.36 RT
    10- .036 ISEN
    11- 1.02 OVP1
    12- 1.02 OVP2
    13- -.035 SFON
    14- -.035 SSTCMP
    15- -.036 GNDP
    16- -.036 DRV2
    Attached Files
    Tags: None
    #2
    Re: TCL 65S421 No Backlight

    Just use a LED tester. Ive had a few of these and it was always the backlight so far, not the psu

    Comment

      #3
      Re: TCL 65S421 No Backlight

      Originally posted by eazybone View Post
      just use a led tester. Ive had a few of these and it was always the backlight so far, not the psu
      +1

      Comment

        #4
        Re: TCL 65S421 No Backlight

        8 out of 10 tvs i get for free/repair are backlight issues, i always do a quick visual check on the boards then test the backlights saves so much time trouble shooting

        Comment

          #5
          Re: TCL 65S421 No Backlight

          Originally posted by vinceroger69 View Post
          8 out of 10 tvs i get for free/repair are backlight issues, i always do a quick visual check on the boards then test the backlights saves so much time trouble shooting
          Agreed. These psus on the Roku TVs do weird things also when then lights have a short. Plus it's pretty much always the BLs lol

          Comment

            #6
            Re: TCL 65S421 No Backlight

            Originally posted by EazyBone View Post
            Agreed. These psus on the Roku TVs do weird things also when then lights have a short. Plus it's pretty much always the BLs lol
            I have actually just fixed a 43 inch roku tv i got for free and yes was backlights at fault, first tapped in screen repair i have done it went ok i just took my time when removing the screen and cleaning it up used 3m foam tape for re assembly.

            Comment

              #7
              Re: TCL 65S421 No Backlight

              It looks like LED2 is bad. The tester stays at 330v when I probe the pins. Thanks

              Comment

                #8
                Re: TCL 65S421 No Backlight

                Yup that's your answer. Next time on these Roku TVs with same problem, just skip right to testing LEDs, then if they are good then look at PSU

                Comment

                Previous template Next
                Working...
                X