A2159 820-01598-06, no power

[floperth]

Hey, as i just became a member i need to hijack this post a little

I got the same board in front of me.
My issue, the board does not power up. it has 20V coming in and
PPBUS_G3H reads 12.56V

I measured around the C3217B (see pictures attached)
Circled in red does not give me a Diode reading while the rest looks ok

https://ibb.co/JKVFtyp
https://ibb.co/TP1W4ps

Any thoughts? i don't have the Boardview which makes it quite hard for a beginner like me.

Thanks guys!

[piernov]

Re: A2159 820-01598-06, no power

You're supposed to make your first post in https://www.badcaps.net/forum/showth...o=newpost&t=12 then you get the ability to create new threads.

Anyway, you got 20V on PPDCIN and even PPBUS_G3H is present so there's no point in looking around the USB-C controllers CD3217.
What's the history of the machine? What's the current consumption on USB-C ammeter?

[floperth]

Re: A2159 820-01598-06, no power

Thanks Piernov, i said hello now...

Unfortunately i don't have a USB-C ampmeter. any other way of telling the consumption?
History is that the mac was in a car crash (car rolled a few times) there was some coca cola in the car too.

i took some shots of the board:
https://ibb.co/VMtCwxK
https://ibb.co/rQCB8ty
https://ibb.co/6b8wt7C
https://ibb.co/StyRmL0
https://ibb.co/r2zQsBD

Thanks for your response Piernov! :-)

[piernov]

Re: A2159 820-01598-06, no power

There's indeed several spots of dirt and corrosion. Make sure you locate every single one of them and take good shots, then you can clean them and see if the components are corroded afterwards.
On the second picture there's damage on a CPU VRM chip — that's often a bad sign but let's hope the CPU survived.

There's no boardview for this board available yet and there's no similar boardview (820-00840 and 820-00850 can give some ideas but they're still very different). At least schematics leaked a few months ago. This is a T2 machine with a pretty complex and obscure power sequence. It's one of the hardest board to start repairing.

Also please attach the pictures directly to your post rather than uploading to an external service.

[floperth]

Re: A2159 820-01598-06, no power

i've taken pictures of all the bad spots and cleaned the board with a fine brush and iso alcohol as best as i could. ISO Alcohol is the only stuff i had at home.
I do have some solder flux somewhere.

So far there's no change in the behavior of the board.

[floperth]

Re: A2159 820-01598-06, no power

So there's boardview available now. which makes this a little more exciting!

p.s piernov the board is in the good hands of paul daniels at the moment (i bet you knew anyway) cheers,

[hitibiti]

Re: A2159 820-01598-06, no power

do you have board view i have the same problem but i found one ic burned i need to know the part number to order it : (

[floperth]

Re: A2159 820-01598-06, no power

just use the search i think you'll find it in this forum

would be nice to know which IC it is...? can you take a photo of it? what is your USB-C meter reading?