1 ON 1 PHONE TUTORING? (how to troubleshoot and how to read schematics better!)

[bruce1129]

I am fixing my first macbook, and I found a few lines that have no power, but I do not really know what to do from there, I'm having trouble reading the schematics properly so I dont know where to backtrack to in order to hunt down the problem that is keeping these certain rails from getting power. the board does not get warm anywhere so I dont know of a short. One diode was burnt in half, but i replaced it already, and its not even on the the lines without voltage. anyway, some one on one phone tutoring would be appreciated and if anyone can help (who knows what theyre doing) i am willing to pay $75 hr for phone tutoring.

 

[peterfixit]

https://www.youtube.com/watch?v=EG8Osy-hNtg&list=PLkVbIsAWN2lsHdY7ldAAgtJug50pRNQv0
259 videos on this subject, its free, I've watched about 60% of them and have fixed 10 out of the 20 boards that have come in with 6 waiting for parts, 4 not fixable
you are already paying to use this forum, use it for specific board issues, for schematics you will need the board view file and open board view, openboardview is free and the board view file comes with the schematic, which comes from laptop-schematics.com, you can pay $20 per schematic or all of them for $275, just watch the videos

 

[bruce1129]

thank you. i have the board view and the schematic already, just need help properly reading the schematic. i cannot tell where the lines originate....very confusing at the moment.

 

[peterfixit]

thank you. i have the board view and the schematic already, just need help properly reading the schematic. i cannot tell where the lines originate....very confusing at the moment.

there are names for each line, you can search them on moth the schematic and the board view, also in the board view you can go from one component to the next just by clicking on them

 

[larossmann]

There is nothing I can solve over the phone I can't solve here. What line is it where you can't tell where it originates from? Let's start from there.

 

[bruce1129]

my board doesnt power on. its receiving power (the back end of the fuse shows full voltage, and an g3 hot has voltage, but somewhere there must be a short bc im getting no power (either that or the power button doesnt work (not sure how to trigger that on a laptop board). what im trying to do is test for the short, but i dont really know where to start bc its hard to tell what is connected to what.

 

[peterfixit]

my board doesnt power on. its receiving power (the back end of the fuse shows full voltage, and an g3 hot has voltage, but somewhere there must be a short bc im getting no power (either that or the power button doesnt work (not sure how to trigger that on a laptop board). what im trying to do is test for the short, but i dont really know where to start bc its hard to tell what is connected to what.

Louis has a video called where to start when everything is missing, or something like that, just watch the videos is you don't know where to start

 

[Glenn]

What card are you working on? Are you using original 85W charger

it is not all cards that auto starts when you plug the charger in

 

[larossmann]

my board doesnt power on. its receiving power (the back end of the fuse shows full voltage, and an g3 hot has voltage, but somewhere there must be a short bc im getting no power (either that or the power button doesnt work (not sure how to trigger that on a laptop board). what im trying to do is test for the short, but i dont really know where to start bc its hard to tell what is connected to what.

The first problem is you said you can't tell where a signal is coming from, but you haven't told me a signal so I can show you where it is coming from.

The second problem is assuming there is a short circuit keeping the machine from turning on.A short circuit means voltage is going to ground when it isn't supposed to because a component on a line has failed in a manner that sends all power to ground. What if I remove a component in a line? What if a signal telling something to turn on is not present?

to begin identifying the problem, go to the page in the schematic where the power rails are listed and measure them. G3H ones should always be present, S5 ones should always be present. After that, then S4, then S3, then S0. Start with the G3H rails and the S5 rails - are there any not present?