820-3437 Not turning on when IO flex cable is connected

XooP

New member
MacBook Air 820-3437, shows no signs of water damage, but the owner thinks he might have spilled something in it for a long time ago.
The board looks completely clean. It starts fine without the IO board flex cable, but as soon as i connect the IO flex it won't start anymore.
I have tried with several known good flex cables and IO boards.

Can anyone give me some pointers?

Thanks
 

2informaticos

Administrator
Staff member
Sounds like damaged LIO connector on MLB.
Check with microscope, see if any pin moves freely.

Also check resistance to ground on all power rails which go to LIO connector, when it is connected; no charger, nor battery present.
Start checking 3V42 line.
 

XooP

New member
Thank you, I forgot to mention. I have already checked the physical condition og the 9500 connector and everything looks good, and every pin sits properly. I'll move on to the power rails.
 

XooP

New member
Strange progress, I can't find any shorts on Power Rails, but I just realized that it starts when the battery is connected, even with the LIO cable
 

XooP

New member
Yes both orange and green light accordingly with charging. Using an original 85W Magsafe 1 with Magsafe 2 adapter. I have assembled the MacBook again since it seems fine with the battery connected. It's for a family member so I don't think I will put more effort into it if it works fine now :)
 

2informaticos

Administrator
Staff member
If you repair Apple stuff, forget such adapter and get original Magsafe 2 charger.
That adapter gives weird problems even with good working boards.
 

XooP

New member
I do have several original Magsafe 2 adapters, this one was free at the moment :), thanks for the advice though. I will not use adapters for repairs in the future :)
 
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