Macbook 820-3115 Green light, no fan spin (Compact edit)

Macbook A1278 ( 820-3115 board ) with symptoms of "just failed one day", showing green light only, no turn on (no fan spin).
Edited down to a compact size to save watching time.

[@TheOtlc56]

Im just starting to a MacBook Pro 2012 A1278 thank to you you just helped me starting my first repair

[@pldaniels]

That's fantastic - have you had a win with the repair?

[@spicyweasel]

Wow... I have the same issue with my board... I'm pretty noob considering component level troubleshooting but I suspect my U7941 is damaged because I think I found some sort of liquid around it and I'm not getting an S5 power rail together with no SMC_PM_G2_EN. Probably because of the crappy power supply I used to use with it. Learnt my lesson.

[@behonest4736]

Hey I m having macbook air A1465 no display caps lock light blinking cpu fan rotate then stop keep repeating same
Please help

[@joeycarr1398]

Good job Paul. Do you know of any good inexpensive microscope to work on mobo's ?

[@pldaniels]

This is about as cheap as you can probably go. The trouble with something like this is that the post mount that the base has will likely obstruct you from freely turning the board around as you work on it. At least the heads are standardised so you can always upgrade to a better base or articulated arm later.
www.unionrepair.com/7-45x-szm45-b1-binocular-industrial-stereo-microscope-with-led-lights.html?currency=USD&sl=en

[@zx8401ztv]

Smashing, that was a nasty looking pcb, i've seen that effect with people that carry a (old type) mobile phone while jogging, blue/green death everywhere, sweat full of salt, yuck yuck :-(.
As the late paul daniels would say "You'll like this, but not a lot" he was right lol.

[@pldaniels]

Yes, salty/crusty stuff :eww:
Yes, have to carry something from the magician.

[@cormacpyper]

lol zx he was a star ..but not alot :)

[@zx8401ztv]

Cormac Pyper, LOL, not bad at magic eather, shame he is gone.

[@graphicscardtech3167]

Why was the U7941 and not the SMC?