820-00165 no backlight

[MaxFix]

Hello all,

Water Damaged.
Cleaned.
8.5V
FB pad is gone (see the picture) and I suppose that is the problem. Question is how do I throw a jumper? From D7701 pin 2 to pin 5 on U7701?
XW7720 is not on the board.

Thanks,
Max

 

[2informaticos]

Sometime is still possible to solder the central point from XW7720.
Scratch a bit and use a fine tip solder.
If not possible, use the two test point from the other side.
Search Louis channel, he has a good video about how to do it.

You must place the tiny wire directly under U7701, on the place of FB pad...

 

[JohnB8812]

If you can, you run a wire from that little nub of the corroded test point to the striped side of the diode. Sometimes the nub is completely gone, and you simply have to run a wire from the A5 ball to the diode which is no fun. See if you can solder to the nub. I also 100% recommend replacing the driver anyways as the feedback trace dying likely screwed with the driver as well.

 

[MaxFix]

No Title

Thanks for your advice guys. Test point is completely gone so i've decided to run a wire from diode to A5 (see pictures). switched it on and it burned my led driver which I replaced first thing before fixing fb line because I thought it was the problem originally. It was my last led driver. I have order some more. Waiting to receive and test again. Hopefully it will work. Will post results next week.

 

[2informaticos]

You didn't consider the help ;(
I told you search Louis channel; he posted one video where show how to do that very easy.
No need to run wire between board sides...

 

[2informaticos]

No Title

In case still have doubts, or no time to search.
However, I recommend you find that video.

 

[MaxFix]

Hi informaticos. Sorry i didnt understand your idea first and i couldnt find the right video among 20 other backlight repairs videos on Louis channel. It is actually super simple.
I will try your solution next week when new led driver arrives!

 

[2informaticos]

Confirm with the boardview that is the correct test point.
Your picture shows a small area only.
You have two test point there for use...

 

[MaxFix]

Yes, worked like a charm. Thanks for your help! I wonder why it failed first time when I threw a jumper to the other side of the board. In theory it should have worked, its the same line?