A1466 Logicboard with hole

[Bob_1972]

Hi guys , this is a MacBook Air A1466 Logicboard - 820-3437. See attached photo. There was once F7700 where the hole is now. Looking at the Boardview it would need around 19 jumper wires. Would anyone attempt this ? if so do you have any advice?

Thanks - Bob

 

[2informaticos]

19 wires for?
Just need to run a wire from any PPBUS_G3H point to F7700.
Solder new fuse in one point only: or bypass it directly.

Be aware on the opposite side, may need to rebuild some traces.
Not necessary if thunderbolt is not used.

 

[Bob_1972]

Super, there is no damage on the opposite side. It also seems R5490 is missing, you can see its gone in the photo.

 

[Bob_1972]

Hi 2informaticos, I have replaced F7700 by soldering pin 2 to its pad and then running a wire to pin 1 of C3080. I have a short on C7712 and C7713. I have a Flir One Pro LT and the attached shows the fuse and Q7706 glowing. Looking around the area C7799 was discoloured so I have replaced it. I have removed Q7706 and still get the short. the amperage is 0.24A and I now get a green light on the charger which I never got prior. I replaced U7701. Any ideas ?

 

[2informaticos]

Where exactly do you note the short?
Power rail name, please.
Did you clean internal edge of the hole?

 

[Bob_1972]

Hi, I have an OL on PPBUS_G3H and I cleaned the edge of the hole with Isopropyl alcohol.

 

[2informaticos]

Then where is the short???
Before, or after Q7706?

 

[Bob_1972]

Hi, I have removed Q7706, F7700 and C7782 and I still see the exact same hotspot. I think the issue is that the short is on the board now, I think. I think this because if I drop alcohol over the area it evaporates very quickly in the hole and I can even see the alcohol sizzling. Is there anything that can be done about this ? obviously I am not at your level or I would not be asking so if you can think of anything else please say as I may not have thought of it.

 

[2informaticos]

Polish the hole edge until short is gone.

 

[Bob_1972]

Hi thanks for coming back to me. I have removed F7700 and re run the wire from the pad where pin 2 of F7700 should go to pin 2 of F7140 and the short has gone. I am getting 225mv on pin 2 of F7140 now. Checking the thermal camera the temprate has gone down and I dont see the same alcohol evaporating of the area with the hold. See image 1. However I have now got a hot spot around Q7130, image2. Can you also advise what to use to polish , I have never done this before.

 

[2informaticos]

Please check in diode mode on power rails and find the short.
If a component heats, should have bad reading on output pin...

 

[Bob_1972]

Thanks I will do this, can you tell me how you would polish the burn hole? I have never needed to do this before.

 

[Bob_1972]

Hi, I know for sure that the short is in the hole, I have scraped and tried to "polish" with a black stick. Can anyone offer any tips of removing shorts like this?

 

[Bob_1972]

With multimeter in diode mode , red probe on ground black probe on pin 2 of F7140 I get 0.002

 

[2informaticos]

That is less than 5 ohm, still short; 2-3 ohm in fact.
I hope you've removed power, before measuring in diode mode.

 

[Bob_1972]

Hi , so yes I did remove the power. I know you are mega busy but is there anything that you can add that might help me here ?