Hi. i am getting 12v on both q7510 and q7520 input but 0v output and getting short to ground after that. Would these 2 transistors have died? They look ok visualy. The board powers up but no chime and black screen,thank you
Hey, I had same your problem and I checked everything all this mac. I though electronics on logic board is work.( MAX15119GTM / PHASE 1/ PHASE 2 ) But AXG PHASE 1 doesn't work. So after I installed bootcamp win 7. AXG PHASE 1 ( VCORE come up and run step well ) I'm sure CPU had a problem about energy controller.
Good afternoon, I have assistance in BRAZIL and is coming much plate macbook for repair, they do not care! could you give me any tips? and its getting me the schematics of the boards? very grateful
Yo lou i have the exact same machine but its not giving video it just beeps one time like theres no memory,tried several memories, cleaned out the slots but still 1 beep, stays on and no video. my vcore is fine as well as the transistor, im also getting my 0.75v on PP0V75_S3_MEM and 1.5v on PP1V5_S3_MEM, im getting all the right values.I know you're a busy man but Any input would be greatly appreciated bro.
If you had a good teacher, you could learn what all of the stuff on that schematic means in a couple of months :) The highest level of math you'd need is high school level.
Your voltage divider explanation would be correct if this were a linear voltage regulator. Alas, it isn't. The mosfets inside of the double package are, individually, either completely ON (very low resistance), or completely OFF (as if they weren't there). This switching voltage waveform, alternating between 12 and 0V is smoothed out by the inductor L7510, shown on the schematic to the right of the mosfets. This forms a so-called switching voltage regulator, with a synchronous rectifier (that's the role of the lower mosfet that switches to ground). If this were a linear voltage regulator, it would need a heatsink, oh, the size of the motherboard, and you'd have 5-10 minute runtime on one battery charge. Linear regulators waste lots of energy - proportionally to the ratio of the output to input voltages. A ratio larger than 12:1 in this case is really a very poor fit for a linear regulator.
You are 100% correct. That is what I get for doing these walkthroughs at 1 am when I am exhausted and in a rush to go home. The only linear like "supplies" you'll see here are simple voltage dividers going to enable pins where there's practically no power. What is important here, and something worth pointing out a) All you really have to now is enough to understand on some basic level what is going on. b) Even if you are half asleep and clueless, you have enough brainpower to figure these things out on your own. One thing I try to beat through to people in all of these videos who go on with this "YOU MUST BE A GENIUS OMG" horsecrap is that you really don't have to be.. and this is a very good example, because going back and listening to what came out of my mouth I sound like a god damn moron. :) This particular machine spent two weeks at a neighboring place before it came here and got done in 45 minutes.. at 12:30 in the morning. Hopefully this serves to prove my point, and provide encouragement to people trying to solve their own problems. Linear regulators aren't something you're going to find most often unless it's either a very low power, non critical, lame ass application(like just jerry rigging the 12v from backlight enable circuit to 3v for enable voltage without having to create another transistor/sgnal network to send the 3v rail to the enable pin), or just for places where the slightly less ripple voltage actually benefits in practical application. You should see the linear power supply I use for the DAC to my home stereo to replace the wall wart.. total waste, but it sounds awesome. :-)
Louis Rossmann In any case, I wanted to make one thing explicit: Your approach to business and to teaching is excellent. You're a real asset to us all. And I don't mind the expletives either :)
Thanks! I probably do have alot to learn from you. People keep asking me to do electronics tutorial videos.. I feel weird doing this kind of thing after flunking out of college repeatedly because I kept failing basic chemistry. :( Under protest I will soon do a very vewry basic video with a strong focus on board repair, and leave out a bunch of generalized info. Would be great to pick your brain before that. As Sam Fields always said, everything I leanred came from not being afraid to show the world just how STUPID I am!!
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Hi. i am getting 12v on both q7510 and q7520 input but 0v output and getting short to ground after that. Would these 2 transistors have died? They look ok visualy. The board powers up but no chime and black screen,thank you
Great videos, Louis
I've only watched a few , but look forward to more , have learned a lot so far. , MacBook Pro ,820-3115-b
Hey, I had same your problem and I checked everything all this mac. I though electronics on logic board is work.( MAX15119GTM / PHASE 1/ PHASE 2 ) But AXG PHASE 1 doesn't work. So after I installed bootcamp win 7. AXG PHASE 1 ( VCORE come up and run step well ) I'm sure CPU had a problem about energy controller.
Love the way you explain shit... well done!
Good afternoon, I have assistance in BRAZIL and is coming much plate macbook for repair, they do not care! could you give me any tips? and its getting me the schematics of the boards?
very grateful
Yo lou i have the exact same machine but its not giving video it just beeps one time like theres no memory,tried several memories, cleaned out the slots but still 1 beep, stays on and no video. my vcore is fine as well as the transistor, im also getting my 0.75v on PP0V75_S3_MEM and 1.5v on PP1V5_S3_MEM, im getting all the right values.I know you're a busy man but Any input would be greatly appreciated bro.
MrNitemare0 Did you solved it? I have exactly the same problem
no buddy i ended up buying another board, even though it seems simple to fix, its really hard to pinpoint the problem, like this guy.
MrNitemare0 Thanks bro....
If you had a good teacher, you could learn what all of the stuff on that schematic means in a couple of months :) The highest level of math you'd need is high school level.
Your voltage divider explanation would be correct if this were a linear voltage regulator. Alas, it isn't. The mosfets inside of the double package are, individually, either completely ON (very low resistance), or completely OFF (as if they weren't there). This switching voltage waveform, alternating between 12 and 0V is smoothed out by the inductor L7510, shown on the schematic to the right of the mosfets. This forms a so-called switching voltage regulator, with a synchronous rectifier (that's the role of the lower mosfet that switches to ground). If this were a linear voltage regulator, it would need a heatsink, oh, the size of the motherboard, and you'd have 5-10 minute runtime on one battery charge. Linear regulators waste lots of energy - proportionally to the ratio of the output to input voltages. A ratio larger than 12:1 in this case is really a very poor fit for a linear regulator.
You are 100% correct. That is what I get for doing these walkthroughs at 1 am when I am exhausted and in a rush to go home. The only linear like "supplies" you'll see here are simple voltage dividers going to enable pins where there's practically no power.
What is important here, and something worth pointing out
a) All you really have to now is enough to understand on some basic level what is going on.
b) Even if you are half asleep and clueless, you have enough brainpower to figure these things out on your own.
One thing I try to beat through to people in all of these videos who go on with this "YOU MUST BE A GENIUS OMG" horsecrap is that you really don't have to be.. and this is a very good example, because going back and listening to what came out of my mouth I sound like a god damn moron. :) This particular machine spent two weeks at a neighboring place before it came here and got done in 45 minutes.. at 12:30 in the morning.
Hopefully this serves to prove my point, and provide encouragement to people trying to solve their own problems.
Linear regulators aren't something you're going to find most often unless it's either a very low power, non critical, lame ass application(like just jerry rigging the 12v from backlight enable circuit to 3v for enable voltage without having to create another transistor/sgnal network to send the 3v rail to the enable pin), or just for places where the slightly less ripple voltage actually benefits in practical application.
You should see the linear power supply I use for the DAC to my home stereo to replace the wall wart.. total waste, but it sounds awesome. :-)
Louis Rossmann In any case, I wanted to make one thing explicit: Your approach to business and to teaching is excellent. You're a real asset to us all. And I don't mind the expletives either :)
Thanks! I probably do have alot to learn from you. People keep asking me to do electronics tutorial videos.. I feel weird doing this kind of thing after flunking out of college repeatedly because I kept failing basic chemistry. :( Under protest I will soon do a very vewry basic video with a strong focus on board repair, and leave out a bunch of generalized info. Would be great to pick your brain before that.
As Sam Fields always said, everything I leanred came from not being afraid to show the world just how STUPID I am!!