Element LED No Backlight

[CraigR]

I have a Element ELEFW327 LED with no backlight. I only see one board in the whole TV. I read where chip U11 can go bad giving results like this so I replaced it and still the same. I can see the picture using a flashlight just no backlight.

[budm]

Re: Element LED No Backlight

Please read these and report the Voltage readings:
https://www.badcaps.net/forum/showth...327#post510582

https://www.badcaps.net/forum/showth...327#post466043

[CraigR]

Re: Element LED No Backlight

UL41
1.25v 2.50v 5.06v
UL51
.5v 1.82v 4.29v
UL1
0v 3.30v 5.08v
UT1
0v 3.31v 5.06v

[budm]

Re: Element LED No Backlight

Your readings do not have the result as these:
https://www.badcaps.net/forum/showpo...97&postcount=4
What did you use for GND?
Also what do you get on the diodes?
https://www.badcaps.net/forum/showpo...40&postcount=1

[CraigR]

Re: Element LED No Backlight

Used a screw for the ground. I edited the results bad ground before.

[budm]

Re: Element LED No Backlight

OK, how about the reading of that link to post #1 for the voltage son those diodes? i wonder if you may have the same problem as shown in that link.

[CraigR]

Re: Element LED No Backlight

D88 138v
D89 185v

[budm]

Re: Element LED No Backlight

The readings are high, that white connector with two pair of wires ( red, gray, red, gray) that go to the LEDs, Can you take the reading at each pin? So far it looks like you have open LED or open connection in the LED string (LED are connected in series like Christmas lights so if one goes open circuit then the whole thing will not light up.
And what are the Voltage rating of those two caps, one is next to the LED connector, and another one is close by?

[CraigR]

Re: Element LED No Backlight

Zero volts on all the connectors for the LED's Big cap is 10uF 450v and the other is 33uF 200v

[budm]

Re: Element LED No Backlight

Zero volts on all the connectors for the LED's Big cap is 10uF 450v and the other is 33uF 200v

I hope you did it correctly, just to be sure, measure the DCV between the two legs of those two caps, and between the Cathode of that Diode I marked and Ground when TV is switched on.
We will need good clear pictures of the bottom side of the board.

[CraigR]

Re: Element LED No Backlight

Here is a pic of the underside. it will take me a bit to solder some wires on those caps to read voltage.

[CraigR]

Re: Element LED No Backlight

Ok, I have No voltage at the bigger cap and No voltage at that diode or the LED and 179.4v at the smaller cap.

[budm]

Re: Element LED No Backlight

The Cathode of the Diode that I marked in the picture is part of the Boost Converter circuit (youi can see SMD power MOSFET and the inductor right next to taht diode), so if you are not getting any DCV at the Cathode with ref to GND, then you have dead boost converter problem or it is not getting any input to feed the Boosted circuit, you will have to trace that out.
This is not going to be an easy tracing due to the board is double sided.
Pictures provided by SHOPJIMMY. http://www.shopjimmy.com/catalogsear...ement+ELEFW327

[CraigR]

Re: Element LED No Backlight

Just went over my head. No boards for it either at shopjimmy or ebay.

[CraigR]

Re: Element LED No Backlight

Scraped TV All boards over $70 so not worth fixing.