Macbook pro 820-2530 troubleshooting

[King_Jorg]

So this system is not turning on, no light on charger when plugged in.
I start troubleshooting and i get 0v everywhere.
Replaced r6905, c6990 and c6999 now i have 3.6v and 17.2v on both sides of r6905.

D6905 has 3.6v on pin 1 but 2.7v on pin 5.

Q7050 has 1v everywhere less pin 4 which has 0.22v.

Pin 4 is CHGR_BGATE which comes from U7000.

U7000 has:
0v on DCIN,
4v on ACIN,
0v on VDD,
1.7v on PP3V42 G3H.

U7000 CHGR_DCIN comes from D7010 wich has 0v on DCIN side but 17.22v on the other side.

I upload schematics see if someone can give a clue.
Thanks in advance.

[piernov]

Re: Macbook pro 820-2530 troubleshooting

Resistance to ground on PP3V42_G3H?

[King_Jorg]

Re: Macbook pro 820-2530 troubleshooting

Lmao i promise i checked that..
I get 0.. Looks like I have a short now.
Ill try to hunt it and update woth news thanks man

[King_Jorg]

Macbook pro 820-2530 short on PP18V5_G3H

So this system has 17.2v on PP18V5_G3H with 0 resistance to ground.

Removed R6905.

Still shorted

R7062 gets 7v instead of those 17v. Removed and board still shorted.

Fuse on that line is ok..

Any ideas?

[piernov]

Re: Macbook pro 820-2530 short on PP18V5_G3H

Remove the fuse and check which side the short is on.

[King_Jorg]

Re: Macbook pro 820-2530 troubleshooting

Thanks piernov,
Short is after fuse, on pin 2.

[King_Jorg]

Re: Macbook pro 820-2530 troubleshooting

Is it normal to get 0L on multimeter when measuring resistance to ground (diode mode red on ground, black on path ) when circuit has no power?

I get 2.6 when there's power on that rail

[piernov]

Re: Macbook pro 820-2530 troubleshooting

Resistance to ground must be measured without any power.

[King_Jorg]

Re: Macbook pro 820-2530 troubleshooting

So im getting 0L on pin1 of that fuse when no power.. What 0L means then?

[piernov]

Re: Macbook pro 820-2530 troubleshooting

O.L. means near infinite resistance.
I'd recommend you to learn how to use a multimeter before trying to fix a Macbook logic board.
After that, all the basic troubleshooting steps are covered by Louis Rossmann on his Youtube channel. He also made a document to learn the basics that you can find in his video description.

[King_Jorg]

Re: Macbook pro 820-2530 troubleshooting

Im doing it man im watching all of them..
Im just trying to learn dude dont have to be mean.
Well after building again all the paths i have no shorts.
I have u7000 not getting power through DCIN cause pp18v5_g3h is not getting through d7010..
Is it possible to skip a diode?
I dont get why power is not going through it.
Everything else is looking fine.

PD. Replay if you can help but if you going to tell me to watch Louis Rossman videos im already doing it for 2 months thanks!
If for whatever the reason is you dont know how to help me or you dont want just dont reply.
Thanks in advance.

[luckydip]

Re: Macbook pro 820-2530 troubleshooting

whats the reistance between pin 17&18 and 27&28 on U7000?

voltages on pin 1,3?

check resistance of r7040

PPBUS_G3H voltage?