820-3115 not recognizing screen

[Chuck60]

Oh ok on my working board I have 1.14v 17/18 that’s the only thing missing on the non working

 

[2informaticos]

Check both boards in the same condition; LCD connected.
Be sure L9080 is good.

 

[Chuck60]

I tested again and I replaced L9080 same thing 0v 17/18 on bad board 1.14V on 17/18 good board.

 

[Chuck60]

Ok both boards measurements are equal in diode mode and ohms. Let’s say I was gonna attempt a pch swap what size solder balls would I use ?

 

[2informaticos]

Stencil must be marked...

 

[Chuck60]

Oh I’m using a bga stencil Or what I think is a bga stencil that just lines up. I will look for the Correct stencil and right down the size or just use solder paste thanks

 

[2informaticos]

That BGA stencil, should have balls size marked on it.

 

[piernov]

Balls should be 0.3mm. Ball size should indeed be marked on the stencil, you can't use a random stencil, only stencil for 6/7 series mobile chipset will line up.
If you have a decent BGA rework station you can buy pre-balled PCH and solder it lead-free. Will save your time and sanity.

 

[Chuck60]

Hi, I just wanted to recap. I wanted to find the exact reason why I wasn’t getting all my signals for lvds. I’m not sure this is correct but on pin 458 of u1800 I have a dead 0.00v short I removed (R2465, R2460, C2465,C2466,C7781,u7800) on this line and on u7800 Pin 1 (PP1V05_S0_PCH_VCCADPLL)
I still have a dead short. I’m guessing it’s directly from PCH. So I’ll go ahead and replace thank you 2informatico and piernov

 

[Chuck60]

Hi, @piernov thank you for you help honestly I’m gonna Use a modified digital cook top So I’m guessing it’s not classified as “decent” and I have a hozan bga hot air from the top. I also have a Quick 861On my desk. I see you’ve already answered my question About buying a new PCH above so I’ll buy it new Let’s see how this goes wish me luck that I’ll pull out a miracle