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Is PP3V3_G3_RTC present? What is the history of this, water, drop, or something else? This could really be anything at this point, needs some more information to be able to advise. No PM_SLP_S4_L pulse could be almost anything.

My best guess there is the battery is pulling down the SMC data line or is bad. Try another battery. U7100 communicates with U5000 on the same data line it uses to communicate with the battery. If it is pulled down, U5000 will not be able to tell U7100 to up the PPBUS_G3H voltage to 12.56v from...

This all points to a bad SMC. Replace the SMC with one from a donor board, a 820-3437.

Pin 3 is the VIN, voltage in pin. We expect here DC in voltage or battery voltage. The battery is 11-12v, the DC in voltage should be 16v. PPDCIN_G3H_OR_PBUS goes through R6990 to send 16v to the voltage in pin. It also goes through R6993 to enable the chip to turn on. Since pin 2 is 16v, I...

Do you have a green light with this now? 17/18 and 27/28 are part of the current sensing circuit. If it can't tell how much current the battery(27/28) and the charger(17/18) are using, it turns off the machine. Those values read normally. 1) Are you getting a green light yet? 2) If you...

What is the history? Liquid, drop, or out of nowhere? Do you get a light on a USB mouse?

Is SMC_RESET_L high? I would reflow the SMC first and see what happens, if SMC_RESET_L is high. SMC_RESET_L has to be high for the SMC to turn on. Make sure to remove the edge bonding and don't let any get stuck under the chip.

The first thing is why is PP3V42_G3H 2.9v instead of 3.425v? That isn't right at all. PPBUS_G3H being 12.23v means the SMC is not running. Is SMC_RESET_L 3.42v? Does the SMC seem corroded? What is diode mode on pin 2 of on R5280 and R5281, with red probe on ground?

It is possible that it thinks you're holding power button when you're not or that it thinks you are trying to reset the SMC. Try it again with a different keyboard. I would hope it is that rather than some random crack in the board that flexes just enough once screwed in for it to stop working.

Have you gone down the rest of the power rails to see what is missing? When you hit the power button on the keyboard does PM_SLP_S4_L pulse for a second? You might need a second set of hands for this.

Look up what U6900 and U6901 look like on any old Unibody board - 820-3115, 820-3330, 820-2936, 820-2879, 820-2915, 820-2850, etc. Then look at the DC in board of the air and find those same two ICs on the Macbook Air DC in board. The Macbook Air has the circuitry that allows the charger to...

A drop typically points to a damaged BGA or a crack inside the board internally which you will not be able to see which makes it a bad candidate for learning. Even for more experienced people like Duke & I these usually wind up in the trash heap. That being said, troubleshooting should begin by...

1) What is the resistance to ground on PPBUS_G3H? 2) What is the resistance between pins 17/18 on U7000? Measure at the pins. This should be around 2-3. 3) What is the resistance between pins 27/28 on U7000? Measure at the pins. This should be around 20. 4) What is the voltage on pin 2 of...

Just Google the number of the board and you'll find them online. We can't distribute them as this is a public forum hosted in the United States and we are already on the radar of you-know-who's lawfirms. A quick google shows laptop-schematics and notebook-schematics have a bunch available.

PPBUS_G3H is created by Q7130 sending pulses of the charger voltage through. Some 16v, some 0v. Some 16v, some 0v. It is supposed to average out to 12.56v through L7130. If Q7130's top transistor shorts and gets stuck, it will not switch. PPBUS_G3H will permanently be 16v. The battery does not...

I don't have the diagram for this in front of me. If it has PICCOLO there is an issue where when PICCOLO goes bad it will not see the SSD below a certain battery percentage, typically 30%. Try again when you drain the battery. If you bring it down to 5-10%, can you reboot the machine and boot...

Goto page 7 or 8 on the schematic where it lists the power rails. Measure and see if you can find which ones are present, which are missing, and which are "pulsing." By pulsing I mean turning on then off rapidly. Check to see if you have a short circuit on any rails. A short circuit is when you...

Yes, it can read the chips used on airs and 13" retinas, you just need an adapter for it.

Firstly no sharing schematics or boardviews here, secondly bios DUMP has nothing to do with schematic or boardview. You need a programmer like a TL866 or something to read the BIOS from the existing chip.

No, the BIOS dump itself, not schematic and boardview.