RCA RLDED5078A (JVC LT-50E350) power board

[olivier.gendron@gmail.com]

Hello friends,

I'm looking for help to fix my RCA tv, everything is fine except no backlight.

I know that the problem is the power board because I cant get any voltage from the led plug.

The board model is : ay160d-4hf12;
I confirm all voltage from con2 - con30 - con4 are good ( green circle ).
I have around 400v coming from the huge cap with the glue on it.
No voltage in Con8 backlight power ( red circle)

Now I'm stuck... any help would be appreciate.

[Andrew F. Ali]

Re: RCA RLDED5078A (JVC LT-50E350) power board

What voltage reading are you getting on the BL-ON pin?

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

What voltage reading are you getting on the BL-ON pin?

Good question ! I'll check when I come back from work. Thanks

[Andrew F. Ali]

Re: RCA RLDED5078A (JVC LT-50E350) power board

The BL-ON pin should be >2V.

[neilc6]

Re: RCA RLDED5078A (JVC LT-50E350) power board

I have replaced led backlights on this model before. Confirm your baclights are good.

[R_J]

Re: RCA RLDED5078A (JVC LT-50E350) power board

Measure the voltage across the connector and monitor it when you first turn on the tv, it will likely come up then drop off if the led string is open.

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

I have replaced led backlights on this model before. Confirm your baclights are good.

R_J , neilc6 , Andrew F. Ali

Thank you guys, I'll check tonight

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

Andrew F. Ali - about 4-5 volts

R_J , neilc6 I think you guys are right ! I have a voltage drop starting at 160 and then nothing. I've check the resistance/continuity of the stripes from the red and white wire and I have nothing, it is probably a short or something. I will remove the screen and check this out. Thank you guys for all the infos. Really appreciate. It must be the backlight.

[R_J]

Re: RCA RLDED5078A (JVC LT-50E350) power board

You can't measure the resistance of the led string itself, there are about 60 led's in series. Be carefull removing the screen and mark or remember the orientation and sequence of the diffuser sheets.
I see shopjimmy is out of stock on the led strips themselves

[neilc6]

Re: RCA RLDED5078A (JVC LT-50E350) power board

This model has a least 2 different backlight configurations. One is 12 strips all the same and the other is a two piece right-left configuration. Strips for the second configuration are more difficult to find.

If you are successful at repairing the backlight, you can can turn down the backlight level in the service menu -> panel setting. MENU-1-1-4-7 with the TV on.

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

Got it ! There was liquid inside. 2 bad leds.

Thanks everybody . One love

[Andrew F. Ali]

Re: RCA RLDED5078A (JVC LT-50E350) power board

I would recommend changing all the backlight strips as you already have it opened up. These Panels are a bitch to open and handle the delicate glass screen.

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

I would recommend changing all the backlight strips as you already have it opened up. These Panels are a bitch to open and handle the delicate glass screen.

Thank you for the recommandation.

[olivier.gendron@gmail.com]

Re: RCA RLDED5078A (JVC LT-50E350) power board

Alright Guy its fixed now ! Thanks for everything.

[Andrew F. Ali]

Re: RCA RLDED5078A (JVC LT-50E350) power board

Good job!! Thanks for the feedback.